Dissertations / Theses on the topic 'Stochastic frontier analysis (SFA)'

This study analyzes the technical efficiencies of Turkish electricity distribution companies (21 in total) throughout 2002 and 2009. For this aim, we used six different model specifications, all of which are generated from two different Stochastic Frontier Analysis (SFA) models (Battese ve Coelli (1992&
1995)). At the end of the estimations of the models, it has been seen that the signs and significance levels of the coefficient estimations are very consistent and satisfactory in all models. We also observed consistency between the coefficient estimations of the different models despite the differences in the magnitudes of the coefficient estimations. For example, all model specifications confirm the presence of increasing returns to scale and of a mild technological progress over time in the market. In addition, among the inputs, all inputs except the quality of the electricity delivered are important in enhancing technical efficiency of the electricity distribution companies, according to the all alternative specifications. Again, all models showed that inefficiency effects rather than random error effects are of crucial importance in Turkish electricity distribution market. As for the efficiency estimations of the alternative models, the main conclusion revealed by our study is that efficiency estimations of the Battese ve Coelli (1995) models are remarkably higher than those of the Battese ve Coelli (1992) models. The efficiency estimation differences between Battese and Coelli (1992&
1995) models can be attributed to the environmental variables included into the Battese ve Coelli (1995) models, which are not generally controlled by electricity distribution companies.

Although the German framework of incentive-based energy regulation appears to be well-defined because it draws from international experience and eliminates several present drawbacks existing with revenue-cap regulation doubts of industry and politicians concerning the application of benchmarking techniques and more importantly, the future industry structure, remain. The regulation scheme is based on experience with energy sector reforms in the US due to it being a precursor in this regard, e.g. by introducing incentive-based regulation as early as 1994 and publishing the relevant data in a very detailed way. This thesis therefore brings together the two issues of certain efficiency measurement problems and the industry restructuring in Germany and the US in order to contribute to the current discussion of robust benchmarking and to provide political implications related to the industry’s structure. Therefore, the application of DEA and SFA constitutes the heart of the whole study. These techniques are applied on German electricity DSOs as well as on data for US electricity DSOs and US gas TSOs. The application to US data can then be used to derive information about business strategies and their success in a sector that is being restructured. The US experience will lead to relevant German policy implications with respect to the future structure of the energy industry in Germany
Der deutsche Regulierungsansatz erscheint im Allgemeinen als ausgewogen, da er zum einen internationale Erfahrungen mit einbezieht und zum anderen bestehenden Schwächen der Erlös-Obergrenzenregulierung berücksichtigt. Dennoch bestehen Zweifel seitens Industrie- und Politvertretern bezüglich der Anwendung von Benchmarking-Techniken und noch bedeutsamer der zukünftigen Industriestruktur. Der regulatorische Rahmen basiert auf Erfahrungen aus der Regulierung der Energiewirtschaft aus den USA, da diese eine Vorreiterrolle in dieser Hinsicht innehaben, beispielsweise aufgrund der frühen Einführung der Anreizregulierung in 1994 und der sehr detaillierten Veröffentlichung der relevanten Daten. Diese Arbeit verknüpft daher diese zwei Aspekte zum einen der Existenz gewisser Problemfelder bei der Effizienzmessung als auch der Umstrukturierung der deutschen Industriestruktur in der Energiewirtschaft. Damit trägt sie zu der aktuellen Diskussion mit Bezug auf robustes Benchmarking bei und liefert zudem politische Implikationen bezüglich der Industriestruktur. Zu diesem Zweck steht die Anwendung der für die deutsche Regulierung der Energienetze relevanten Benchmarking-Techniken (Data Envelopment Analysis (DEA) und Stochastic Frontier Analysis (SFA)) im Zentrum der gesamten Studie. Die empirischen Analysen beziehen sich dabei auf deutsche Elektrizitätsverteilnetzbetreiber sowie auf Elektrizitätsverteilnetzbetreibern und Ferngasgesellschaften aus den USA. Die Analysen von US Daten können dann genutzt werden, um gehaltvolle Informationen über Unternehmensstrategien und deren Erfolg in einem restrukturierten Sektor zu gewinnen. Diese Erfahrungen münden dann in Schlussfolgerungen und Empfehlungen für die deutsche Regulierung und Industriestruktur der deutschen Energienetzwirtschaft

Although the German framework of incentive-based energy regulation appears to be well-defined because it draws from international experience and eliminates several present drawbacks existing with revenue-cap regulation doubts of industry and politicians concerning the application of benchmarking techniques and more importantly, the future industry structure, remain. The regulation scheme is based on experience with energy sector reforms in the US due to it being a precursor in this regard, e.g. by introducing incentive-based regulation as early as 1994 and publishing the relevant data in a very detailed way. This thesis therefore brings together the two issues of certain efficiency measurement problems and the industry restructuring in Germany and the US in order to contribute to the current discussion of robust benchmarking and to provide political implications related to the industry’s structure. Therefore, the application of DEA and SFA constitutes the heart of the whole study. These techniques are applied on German electricity DSOs as well as on data for US electricity DSOs and US gas TSOs. The application to US data can then be used to derive information about business strategies and their success in a sector that is being restructured. The US experience will lead to relevant German policy implications with respect to the future structure of the energy industry in Germany.
Der deutsche Regulierungsansatz erscheint im Allgemeinen als ausgewogen, da er zum einen internationale Erfahrungen mit einbezieht und zum anderen bestehenden Schwächen der Erlös-Obergrenzenregulierung berücksichtigt. Dennoch bestehen Zweifel seitens Industrie- und Politvertretern bezüglich der Anwendung von Benchmarking-Techniken und noch bedeutsamer der zukünftigen Industriestruktur. Der regulatorische Rahmen basiert auf Erfahrungen aus der Regulierung der Energiewirtschaft aus den USA, da diese eine Vorreiterrolle in dieser Hinsicht innehaben, beispielsweise aufgrund der frühen Einführung der Anreizregulierung in 1994 und der sehr detaillierten Veröffentlichung der relevanten Daten. Diese Arbeit verknüpft daher diese zwei Aspekte zum einen der Existenz gewisser Problemfelder bei der Effizienzmessung als auch der Umstrukturierung der deutschen Industriestruktur in der Energiewirtschaft. Damit trägt sie zu der aktuellen Diskussion mit Bezug auf robustes Benchmarking bei und liefert zudem politische Implikationen bezüglich der Industriestruktur. Zu diesem Zweck steht die Anwendung der für die deutsche Regulierung der Energienetze relevanten Benchmarking-Techniken (Data Envelopment Analysis (DEA) und Stochastic Frontier Analysis (SFA)) im Zentrum der gesamten Studie. Die empirischen Analysen beziehen sich dabei auf deutsche Elektrizitätsverteilnetzbetreiber sowie auf Elektrizitätsverteilnetzbetreibern und Ferngasgesellschaften aus den USA. Die Analysen von US Daten können dann genutzt werden, um gehaltvolle Informationen über Unternehmensstrategien und deren Erfolg in einem restrukturierten Sektor zu gewinnen. Diese Erfahrungen münden dann in Schlussfolgerungen und Empfehlungen für die deutsche Regulierung und Industriestruktur der deutschen Energienetzwirtschaft.

Aquesta tesi aborda l'aplicació a la indústria aeroportuària d'enfocaments metodològics alternatius als models convencionals classificats com a mètodes no paramètrics i paramètrics. L'objectiu és estimar i confirmar la coherència de l'eficiència dels aeroports espanyols a través del temps. Per tant, s'utilitzen diversos enfocaments per superar limitacions específiques que les metodologies presenten quan es comparen. Dins de les tècniques no paramètriques s'utilitza l'Anàlisi Envoltant de Dades, Data Envelopment Analysis (DEA), i com a models paramètrics, l'Anàlisi de Frontera Estocàstica, Stochastic Frontier Analysis (SFA). DEA s'ha utilitzat àmpliament a tot el món en la indústria aeroportuària i alguns estudis fan referència al cas espanyol. No obstant això, els models de DEA convencionals presenten algunes limitacions; per exemple, tendeixen a no incorporar efectes relacionats amb el temps. La literatura mostra la manca d'ús del SFA en estudis empírics. Per tant, aquesta Tesi reflecteix coneixements rellevants de l'aplicació al sistema aeroportuari espanyol. Una qüestió important en relació amb pocs estudis tenint en compte els aeroports espanyols és la falta d'informació financera individual rellevant publicada per AENA. AENA és una empresa governamental que gestiona tots els aeroports espanyols. El grau de centralització de la gestió és fins l’extrem que els gestors dels aeroports no poden decidir polítiques comercials (per exemple, el preu i la qualitat dels serveis prestats). A més, els estudis no qüestionen ni avaluen críticament la fiabilitat de les dades amb respecte si són una representació fidel de com els aeroports operen. Aquesta tesi és una recopilació de capítols (quatre documents d'investigació) i un document en curs. Tots els treballs són empírics amb objectius específics per tal d'analitzar els aeroports des de diferents perspectives, incloent-hi la ubicació geogràfica i l'atractiu turístic. En primer lloc, un dels principals problemes abordats en aquesta tesi és la fiabilitat de les dades aportades per AENA, especialment pel que fa a la inversió (cost de capital). En segon lloc, calcular l'eficiència individual dels aeroports i avaluar la coherència dels aeroports més eficients no només a través del temps, sinó recolzada per l'aplicació dels dos enfocaments metodològics establerts. Recomanacions de gestió i actuacions polítiques són proveïdes per tal de millorar l'eficiència global del sistema aeroportuari espanyol. Tots els treballs s'han presentat en conferències internacionals rellevants a la indústria aeroportuària i d’aviació i també en conferències metodològiques. Amb l'excepció del cinquè treball (treball en curs), tots els treballs s'han enviat a revistes indexades (peer review) citades al Journal Citation Reports (JCR) i actualment estan en revisió. Algunes extraccions s'han publicat com a casos d'estudi i articles de difusió (The Public Sphere Journal of Public Policy, febrer de 2017; Inside O.R., març de 2018).
This Thesis addresses the application to the airport industry of alternative methodological approaches to the conventional models commonly classified as non-parametric and parametric methods. The aim is to estimate and to confirm the consistency of the Spanish airports’ efficiency across time. Therefore, several approaches are used in order to overcome specific limitations that the methodologies present compared to the other. Within the non-parametric techniques Data Envelopment Analysis (DEA) is used and as parametric models, Stochastic Frontier Analysis (SFA). DEA has been extensively used worldwide in the airport industry and some studies refer to the Spanish case. Nevertheless, the conventional DEA models present some limitations; for example, they tend not to incorporate time related effects. The literature shows a lack of usage of SFA in empirical studies. Therefore, relevant insights are to be learned from the application to the Spanish airport system. One important matter regarding few studies considering the Spanish airports is the lack of individual relevant financial information published by AENA. AENA is a government-owned company and manager of all the Spanish airports. The degree of centralisation of management is to the extent that airports managers cannot decide commercial policies (e.g. price and quality of the services provided). Additionally, the studies neither critically question nor assess the reliability of the data regarding representing a fair and true view of how the airports are performing from an operational perspective. This Thesis is a compilation of chapters (four research papers) and one paper in progress. All the papers are empirical base with specific objectives in order to analyse the airports from different perspectives including the geographical location and the tourism attractiveness. Firstly, one major problem addressed in this Thesis is the reliability of the data provided by AENA, particularly with respect to investment (cost of capital). Secondly, to estimate the individual efficiencies of the airports and to evaluate the consistency of the most efficient airports not only across time, but supported by the application of the two stated methodological approaches. Managerial and policymakers’ recommendations are drawn to improve the overall efficiency of the Spanish airport system. All the papers have been presented in international conferences relevant in the airport and aviation industry and also in methodological conferences. With the exception of the fifth paper (ongoing work), all the papers have been sent to refereed journals (peer review) cited at the Journal Citation Reports (JCR) and they are currently under review. Some extractions have been published as case studies and dissemination articles (The Public Sphere Journal of Public Policy, February 2017; Inside O.R., March 2018)

For as long as managed mutual funds have been in existence there has been a desire to accurately assess their relative performance against each other, and also their respective performance in relation to an appropriate stock market index. There has been a specific interest in whether the expensive, professionally managed mutual funds can justify their high cost with respect to low cost, simple index trackers by producing superior, post-cost performance, and this proposition is implicitly tested within this thesis. The aim of this thesis is to undertake an empirical assessment of the managerial performance of mutual funds utilising a three-stage DEA-SFA-DEA methodology which combines linear mathematical programming (DEA) and stochastic frontier analysis (SFA). Specifically, this thesis focuses on evaluating the managerial performance of UK domiciled open-ended investment companies (OEICs) and unit trusts (UTs) over a three year period from 1st January 2008 to 31st December 2010. Various DEA models are utilised including CCR, BCC and SBM DEA models with various orientations, and also versions of these DEA models which make use of the SORM procedure. These are used to carry out an initial evaluation of the managerial performance of the OEICs/UTs, before two of these DEA models are combined with SFA regression analysis in a three-stage DEA-SFA-DEA methodology to purge the influence of environmental factors and statistical noise, thus leading to a more robust evaluation of the true managerial performance of the OEICs/UTs under assessment. The results of this thesis extend support to the premise of the Efficient Market Hypothesis (EMH) that financial markets are information efficient , and thus it is not possible, given the information available when the investment is made, to consistently obtain returns in excess of the average market return on a risk-adjusted basis, and this thesis does so through the use of a novel approach.

tese de Doutoramento em Ciências Sociais na Especialidade de Administração Pública
Nesta investigação foram estudadas as eficiências e as produtividades das instituições portuguesas do ensino superior público: universidades e institutos politécnicos. Na análise consideraram-se oito períodos académicos: 2000-2001 a 2007-2008. Recorrendo à metodologia Data Envelopment Analysis (DEA), propôs-se uma abordagem que, até à presente data, não foi utilizada para o ensino superior: Analisar a eficiência e a produtividade tendo como base os conceitos de eficiência e super eficiência não radial. Foi também analisado o impacto na eficiência de factores não discricionários. As análises foram efectuadas tendo como suporte o modelo desenvolvido e programado. As conclusões mais relevantes foram: Globalmente, no período 2000-2008, as universidades e os institutos politécnicos melhoraram as suas eficiências relativas e produtividades; A assimetria regional tem impacto na eficiência.
In this research efficiency and productivity of the Portuguese public higher education institutions were studied: universities and polytechnics. The analysis covered eight academic periods: 2000-2001 to 2007-2008. Using Data Envelopment Analysis methodology (DEA), proposed an approach that, to date, has not been used for higher education: Analyze the efficiency and productivity based on the concept of non-radial efficiency and super-efficiency. It was also analysed the impact on efficiency of non-discretionary factors. The analysis were carried out with support of the model developed and programmed. The most relevant conclusions were: overall, in the 2000-2008 period, universities and polytechnics have improved their relative efficiencies and productivity; regional development has impact on efficiency.

This paper provides a systematic review of the literature that employs stochastic frontier analysis to measure the efficiency of higher education institutions. The overview opens with a look at the general development of the literature, before emphasis is laid on the methodical aspects. Focus is thereby placed on the necessary underlying assumptions and the employed specifications, discussing their advantages and drawbacks. Afterwards, the factors that were specified in the literature, including the input and output variables, as well as the determinants of efficiency, are discussed in detail. Based on the insights of the literature review, the paper highlights some of the existing deficiencies and ways forward. To our knowledge, the present study provides the first systematic review on the usage of the stochastic frontier analysis to measure efficiency in the higher education sector.

Stochastic frontier analysis is an exciting method of economic production modeling that is relevant to hospitals, stock markets, manufacturing factories, and services. In this paper, we create a new model using the normal distribution and truncated skew-Laplace distribution, namely the normal-truncated skew-Laplace model. This is a generalized model of the normal-exponential case. Furthermore, we compute the true technical efficiency and estimated technical efficiency of the normal-truncated skewed-Laplace model. Also, we compare the technical efficiencies of normal-truncated skewed-Laplace model and normal-exponential model.

From the idea of efficiency raised by Koopmans in 1951, and the panel data first introduced into the efficiency analysis by Pitt and Lee (1981) and Schmidt and Sickles (1984), the techniques of stochastic frontier analysis are fast developed and the applications of stochastic frontier are widely used in different areas, such as education, industry and hospital. But most researchers focus on only one aspect, either the development of new models or empirical applications. This thesis attempts to fill the gap to get a general idea of the properties of different panel data stochastic frontier models, on both statistical aspects and economic aspects, by the comparison of different models applied to different production applications. The thesis is also attempt to shed light on whether particular panel data stochastic frontier models are better suited to different data sets. The models selected capture the simplest situation, with no heterogeneity or heteroscedasticity, and complicated ones, with exogenous variables included in the models. Not only the classical models, such as the Pitt and Lee (1981) and Battese and Coelli (1992.1995), but also the new developed models, such as the latent class model and fixed management model are detected in the thesis. On the economic aspect, the data selected captures both microeconomic and macroeconomic, with the application to the World GDP and the Italian manufacturing industry. The results show that: the panel data stochastic frontier models perform better on the microeconomic level than on the macroeconomic level; the classical models perform better than the new developed ones; some panel data stochastic frontier models make ideal assumptions but the requirements to the dataset are hard to achieve; that the influence from the exogenous variables is quite strong.

Using the stochastic frontier analysis (SFA) model, this research measures total-factor energy efficiency (TFEE) for 21 emerging market economies (EMEs) by analyzing the panel data collected from World Bank indicators, which stretches from 1990 up to 2015. Capital stock, labor force, carbon dioxide, and gross domestic product (GDP) are input variables and energy use is used as the output variable, while renewable energy consumption and urban population are the environmental variables. The results provided not only the TFEE scores but also the factors behind inefficiency. Note that statistical noise is considered while counting for TFEE. Firstly, Korea, Peru, Thailand, Greece, and Mexico perform better concerning energy efficiency than other countries in Emerging Market Economies (EMEs). Secondary, the energy efficiency scores from 1990 to 2015 of the 21 countries exhibit a gradual upward trend except for Turkey, South Africa, Malaysia, Russia, Brazil, Poland, and Egypt that exhibited technical inefficiencies. Lastly, as it has also been revealed by (Hsiao et al., 2018), the inefficiency estimates, the higher the renewable energy consumption, and urban population the higher TFEE scores.

This thesis analyzes the profit efficiency of the Turkish banking sector after the restructuring program by using Stochastic Frontier Approach. 28 banks are included in the analysis and the data belongs to the period 2002-2009. Profit efficiency scores of 28 banks are estimated by SFA. When the efficiency scores are analyzed according to the ownership status, profit efficiency scores of the state owned banks are found higher than other bank groups. Moreover, according to the asset size, large scale banks&rsquo
profit efficiency scores are found to be higher than the medium and small scale banks.

About 75% of human food in the 21st century consists of just 12 crops, though specific crops vary among nations. Modern technology has allowed development of innovative food and non-food uses for these commodities. For instance, corn (maize (Zea mays L.)) is produced for many purposes, including food, livestock feed, biofuels, fiber for clothing, etcetera. Scientists project the human population will reach 9.2 billion in next 20 years—an 18% increase from the 2020 population of 7.8 billion—resulting in increased demand for corn and other crops. Hence, farmers must increase total crop production to meet demand; however, local agricultural resource endowments such as climate, land and water availability, and soil attributes constrain production. Perhaps the quickest yield and efficiency improvements will result from farm management practices that tailor input applications to match accurate seasonal weather forecasts. Regional seasonal weather forecasts would enable farmers to optimize yields by reducing yield risk from extreme weather events, as well as from less extreme inter-annual weather variability. Improved productive efficiency is also critical to reducing environmental harms, e.g. contaminated runoff from excessive agricultural input use. The objective of this dissertation is to estimate the corn yield frontier and efficiency measures based on agricultural input management and weather. This research contributes to an enhanced understanding of how the corn yield frontier responds to inter-annual weather variations, and how it may shift with climate change. The first chapter summarizes three main topics—farm technology, climate change and weather variability, and methods for evaluating production efficiency. The second presents estimated corn yield frontiers and efficiency measures based on stochastic frontier and data envelopment analyses for nine North Dakota Agricultural Statistics Districts from 1994 to 2018. The third presents corn yield efficiency measures for five states: Minnesota, North Dakota, Nebraska, South Dakota, and Wisconsin from 1994 to 2018. The results reveal the major causes of inter-annual yield variation are variability of rainfall and temperature. Development of accurate growing-season weather forecasts is likely to result in high value-added for farmers and downstream agribusinesses. Federal, state, and private research funding in seasonal weather forecasting would probably be well invested.

The question of public education is of importance for a society and its citizens as education is contributing to the stability of a democratic society and affects the expected future income levels for the individuals receiving it. A significant share of the Swedish GDP is devoted to the provision of educational services which raises the necessity of monitoring the use of these resources. This thesis endeavoured to estimate a production possibility frontier and the relative efficiency of Swedish upper secondary schools. To accomplish this then Stochastic Frontier Analysis was implemented. Data on student results, teacher ratio and students’ socioeconomic characteristics for individual schools during the scholastic years of 2006/2007 through 2015/2016 gathered from the Swedish National Agency for Education was used in this study. The effects of competition on school performance and the relative efficiency of public and independent schools were two factors of interest in the thesis. The results of the analysis point toward a possible positive relationship between local school competition and student results, that Swedish secondary schools could have high average levels of technical efficiency and that the type of the principal organiser might be of minor importance for school efficiency.

This thesis gives an overall view of measuring efficiencies in the Egyptian textile and apparel industry via stochastic frontier analysis (SFA) and data envelopment analysis (DEA). Differences between the SFA and the DEA can lead to different estimates for some, or all of the units in an analysis. Measuring efficiency through production process, (inputs and outputs), lacking factors affecting supply chain operations and other key factors, such as value-adding capabilities, exchange rates, time, inventory turnover, quality, logistics, etc. can lead to inaccurate measures. Thus, to ensure accurate efficiency measures, these factors have to be considered. Techniques used are; SFA time-varying and metafrontier. Constructing a single production frontier based on all data points would cause an unfitting benchmark due to differences in production technologies, location, ownership type, etc. Hence, metafrontier allows grouping firms with similar characteristics into a separate group frontier for each region with single metafrontier applied to all groups. Empirical results show clear variability in efficiencies between private and public firms and shows that efficiency scores vary, when assessed against the metafrontier. The evidence also shows the major role of the supply chain factors in improving efficiencies for public firms.

[From the introduction]: The thesis is organised as follows. In Chapters 1 and 2 we present a review of the existing literature. Chapter 1 analyses the role of incentives and human capital attributes as mechanisms for determining performance. Much of the previous literature analyses manager performance using wage equations. What is unique in our approach is that we are able to generate a direct measure of managerial performance. The background to the methodology used is provided in Chapter 2. Here we explore the growing literature on production frontier analysis. We are particularly interested in the available estimation procedures and how previous sports studies have utilised this framework in estimating efficiency. A discussion of the football industry is the focus of Chapter 3, while in Chapter 4 we develop the theoretical model of manager performance. Data and methodological issues are addressed in Chapter 5. Chapters 6 and 7 contain the empirical results. In Chapter 6 we generate managerial efficiency scores and consider how alternative input and output measures and alternative estimation procedures affect these scores. Using the preferred model from Chapter 6, Chapter 7 provides a detailed account of how human capital factors and incentives shape efficiency and some preliminary results as to whether the manager actually matters. Finally, Chapter 8 provides some conclusions and recommendations in the light of the empirical results.

Thesis (Ph. D.)--University of Kentucky, 2009.
Title from document title page (viewed on October 29, 2009). Document formatted into pages; contains: ix, 153 p. : ill. (some col.). Includes abstract and vita. Includes bibliographical references (p. 143-152).

Despite measures on the European level to increase the compatibility between the HE sectors of the member states, the recent literature exposes variations in their efficiencies. To gain insights into these differences we split the efficiency term according to the two management levels each university is confronted with. Utilizing a recent advancement in the method to measure efficiency, we separate short-term (transient) and long-term (persistent) efficiency, while controlling for unobserved institution specific heterogeneity. While the first term reflects the efficiency of the individual universities working within the country, the second term echoes the influence of the country specific overall HE structure. The cross-country comparison displays if the overall efficiency difference between countries is related to individual performance of their universities or their HE structure. This allows more purposeful policy recommendation and expands the literature regarding the efficiency of universities in a fundamental way. Choosing Italy and Germany as two important illustrative examples we can take advantage of a novel dataset including characteristics of institutions in both countries for an exceptional long period of time from 2001 to 2011. We show that the Italian universities exhibit a higher overall efficiency value than their German counterparts. With the individual universities working at the upper bound of efficiency in both countries, the overall inefficiency as well as the gap between the countries is caused by persistent, structural inefficiency. To expedite a true European Area of Higher Education future measures should hence aim at the country specific structure, not solely at affecting the activities of single universities.

Cette étude porte sur le développement d’un outil de contrôle qualité basé sur l’expérience, dérivé du concept de frontière stochastique en économie et s’appuyant sur des connaissances géométriques spécifiques au patient pour améliorer la qualité des traitements de curiethérapie à haut débit de dose pour le cancer de la prostate. Cent plans cliniques de curiethérapie à haut débit de dose de la prostate ont été utilisés dans cette étude, dans laquelle l’échographie transrectale était la seule modalité d’imagerie. Une fraction unique de 15 Gy a était prescrite à tous ces patients. Un algorithme de recuit simulé de planification inverse a été appliqué pour réaliser tous les plans et Oncentra Prostate a été employé comme système d’imagerie et de planification du traitement en temps réel. Les recommandations relatives aux paramètres de dose de la société américaine de curiethérapie pour la cible et les organes à risque ont été suivies. Les relations entre les paramètres géométriques et les paramètres dosimétriques d’intérêt sont examinées. Les paramètres géométriques sont liés aux dimensions anatomiques des patients et ceux associés aux cathéters. Pour déterminer les paramètres géométriques dominants dans un modèle de frontière stochastique donné, les relations monotones entre les paramètres géométriqueset les paramètres dosimétriques d’intérêt sont mesurées avec une approche non paramétrique, à savoir le coefficient de corrélation de Spearman. Ensuite, une recherche de force brute est effectuée pour un modèle donné dans lequel différents modèles, incluant toutes les combinaisons possibles des paramètres géométriques dominantes, sont optimisés. L’optimisation est accomplie en utilisant une méthode de vraisemblance maximale implémentée dans le progiciel de calcul statistique R, avec son algorithme de recuit simulée généralisée. Le test du rapport de vraisemblance et sa valeur-p correspondante sont utilisés pour comparer la signification statistique de l’ajout de nouveaux paramètres géométriques aux modèles. Un modèle de production pour la cible et un modèle de coût pour chacun des organes à risque sont développés pour le traitement par curiethérapie à haut débit de dose guidé par l’échographie transrectale. De plus, pour valider si chacun des modèles développés est universel, nous l’appliquons à une autre catégorie de traitement de la curiethérapie à haut débit de dose, dans laquelle la tomodensitométrie était utilisée comme modalité d’imagerie plutôt que de l’échographie transrectale. Ainsi, une nouvelle cohorte de cent plans cliniques curiethérapie à haut débit de dose guidés par la tomodensitométrie est prise en compte. Un modèle de frontière stochastique de production pour la cible et trois modèles de coût pour les organes à risque basés sur la tomodensitométrie sont développés. Enfin, les modèles intégrés de la tomodensitométrie et de l’échographie transrectale sont comparés.
This thesis focuses on developing an experience-based quality control (QC) tool, derived from the concept of stochastic frontier (SF) analysis in economics and based on patient-specific geometric knowledge to improve the quality of the high-dose-rate brachytherapy (HDR-BT) treatment for prostate cancer. One hundred clinical HDR prostate BT plans, using the transrectal ultrasound (TRUS) asthe only imaging modality, all treated with a single fraction of 15 Gy, and made using Inverse PlanningSimulated Annealing (IPSA) algorithm, are studied. Also, Oncentra Prostate system is employed as the real-time 3D prostate imaging and treatment planning system. American Brachytherapy Society dose parameter recommendations for target and organs at risk (OARs) were followed. Relationships between all the different geometric parameters (GPs) and the four dosimetric parameters (DPs) V100 of the prostate, V75 of the bladder and rectum, and D10 of the urethra were examined. Geometricinformation of the patients and catheters are considered as different GPs. To find the dominant GPs in a given SF model, monotonic relationships between the GPs and DPs of interest are measured using a nonparametric approach: the Spearman correlation coefficient. Then, to determine the optimal SF model for each of the target production SF, and the OARs cost SF models, brute-force searches are performed. Different SF models including all the possible combinations of the dominant GPs in the SF model under study are optimized. Optimization is done using a maximum likelihood method implemented in the statistical computing package R, along with its Generalized Simulated Annealing algorithm. The likelihood ratio test and its corresponding p-value are used to compare the statistical significance of adding new GPs to SF models. A production SF (PSF) model for the target, and a costSF (CSF) model for each of the bladder, rectum, and urethra are developed for TRUS-guided HDR-BTtreatment. The difference between the dose value of a plan obtained by IPSA and the one predicted by an SF model is explored. Additionally, to verify if each of the models developed for the TRUS-guided category of the HDR-BT treatment for prostate is universal, we apply it on another category of HDR-BT treatment, in which computed tomography (CT) was used as the imaging modality. So, a different cohort of one hundred clinical CT-guided HDR-BT plans is taken into consideration. A target production SF and three OARs cost SF models are developed for the CT-based plans. Subsequently, the built-in SF models for the TRUS-based and CT-based plans are compared.

Cette étude porte sur le développement d’un outil de contrôle qualité basé sur l’expérience, dérivé du concept de frontière stochastique en économie et s’appuyant sur des connaissances géométriques spécifiques au patient pour améliorer la qualité des traitements de curiethérapie à haut débit de dose pour le cancer de la prostate. Cent plans cliniques de curiethérapie à haut débit de dose de la prostate ont été utilisés dans cette étude, dans laquelle l’échographie transrectale était la seule modalité d’imagerie. Une fraction unique de 15 Gy a était prescrite à tous ces patients. Un algorithme de recuit simulé de planification inverse a été appliqué pour réaliser tous les plans et Oncentra Prostate a été employé comme système d’imagerie et de planification du traitement en temps réel. Les recommandations relatives aux paramètres de dose de la société américaine de curiethérapie pour la cible et les organes à risque ont été suivies. Les relations entre les paramètres géométriques et les paramètres dosimétriques d’intérêt sont examinées. Les paramètres géométriques sont liés aux dimensions anatomiques des patients et ceux associés aux cathéters. Pour déterminer les paramètres géométriques dominants dans un modèle de frontière stochastique donné, les relations monotones entre les paramètres géométriqueset les paramètres dosimétriques d’intérêt sont mesurées avec une approche non paramétrique, à savoir le coefficient de corrélation de Spearman. Ensuite, une recherche de force brute est effectuée pour un modèle donné dans lequel différents modèles, incluant toutes les combinaisons possibles des paramètres géométriques dominantes, sont optimisés. L’optimisation est accomplie en utilisant une méthode de vraisemblance maximale implémentée dans le progiciel de calcul statistique R, avec son algorithme de recuit simulée généralisée. Le test du rapport de vraisemblance et sa valeur-p correspondante sont utilisés pour comparer la signification statistique de l’ajout de nouveaux paramètres géométriques aux modèles. Un modèle de production pour la cible et un modèle de coût pour chacun des organes à risque sont développés pour le traitement par curiethérapie à haut débit de dose guidé par l’échographie transrectale. De plus, pour valider si chacun des modèles développés est universel, nous l’appliquons à une autre catégorie de traitement de la curiethérapie à haut débit de dose, dans laquelle la tomodensitométrie était utilisée comme modalité d’imagerie plutôt que de l’échographie transrectale. Ainsi, une nouvelle cohorte de cent plans cliniques curiethérapie à haut débit de dose guidés par la tomodensitométrie est prise en compte. Un modèle de frontière stochastique de production pour la cible et trois modèles de coût pour les organes à risque basés sur la tomodensitométrie sont développés. Enfin, les modèles intégrés de la tomodensitométrie et de l’échographie transrectale sont comparés.
Cette étude porte sur le développement d’un outil de contrôle qualité basé sur l’expérience, dérivé du concept de frontière stochastique en économie et s’appuyant sur des connaissances géométriques spécifiques au patient pour améliorer la qualité des traitements de curiethérapie à haut débit de dose pour le cancer de la prostate. Cent plans cliniques de curiethérapie à haut débit de dose de la prostate ont été utilisés dans cette étude, dans laquelle l’échographie transrectale était la seule modalité d’imagerie. Une fraction unique de 15 Gy a était prescrite à tous ces patients. Un algorithme de recuit simulé de planification inverse a été appliqué pour réaliser tous les plans et Oncentra Prostate a été employé comme système d’imagerie et de planification du traitement en temps réel. Les recommandations relatives aux paramètres de dose de la société américaine de curiethérapie pour la cible et les organes à risque ont été suivies. Les relations entre les paramètres géométriques et les paramètres dosimétriques d’intérêt sont examinées. Les paramètres géométriques sont liés aux dimensions anatomiques des patients et ceux associés aux cathéters. Pour déterminer les paramètres géométriques dominants dans un modèle de frontière stochastique donné, les relations monotones entre les paramètres géométriqueset les paramètres dosimétriques d’intérêt sont mesurées avec une approche non paramétrique, à savoir le coefficient de corrélation de Spearman. Ensuite, une recherche de force brute est effectuée pour un modèle donné dans lequel différents modèles, incluant toutes les combinaisons possibles des paramètres géométriques dominantes, sont optimisés. L’optimisation est accomplie en utilisant une méthode de vraisemblance maximale implémentée dans le progiciel de calcul statistique R, avec son algorithme de recuit simulée généralisée. Le test du rapport de vraisemblance et sa valeur-p correspondante sont utilisés pour comparer la signification statistique de l’ajout de nouveaux paramètres géométriques aux modèles. Un modèle de production pour la cible et un modèle de coût pour chacun des organes à risque sont développés pour le traitement par curiethérapie à haut débit de dose guidé par l’échographie transrectale. De plus, pour valider si chacun des modèles développés est universel, nous l’appliquons à une autre catégorie de traitement de la curiethérapie à haut débit de dose, dans laquelle la tomodensitométrie était utilisée comme modalité d’imagerie plutôt que de l’échographie transrectale. Ainsi, une nouvelle cohorte de cent plans cliniques curiethérapie à haut débit de dose guidés par la tomodensitométrie est prise en compte. Un modèle de frontière stochastique de production pour la cible et trois modèles de coût pour les organes à risque basés sur la tomodensitométrie sont développés. Enfin, les modèles intégrés de la tomodensitométrie et de l’échographie transrectale sont comparés.
This thesis focuses on developing an experience-based quality control (QC) tool, derived from the concept of stochastic frontier (SF) analysis in economics and based on patient-specific geometric knowledge to improve the quality of the high-dose-rate brachytherapy (HDR-BT) treatment for prostate cancer. One hundred clinical HDR prostate BT plans, using the transrectal ultrasound (TRUS) asthe only imaging modality, all treated with a single fraction of 15 Gy, and made using Inverse PlanningSimulated Annealing (IPSA) algorithm, are studied. Also, Oncentra Prostate system is employed as the real-time 3D prostate imaging and treatment planning system. American Brachytherapy Society dose parameter recommendations for target and organs at risk (OARs) were followed. Relationships between all the different geometric parameters (GPs) and the four dosimetric parameters (DPs) V100 of the prostate, V75 of the bladder and rectum, and D10 of the urethra were examined. Geometricinformation of the patients and catheters are considered as different GPs. To find the dominant GPs in a given SF model, monotonic relationships between the GPs and DPs of interest are measured using a nonparametric approach: the Spearman correlation coefficient. Then, to determine the optimal SF model for each of the target production SF, and the OARs cost SF models, brute-force searches are performed. Different SF models including all the possible combinations of the dominant GPs in the SF model under study are optimized. Optimization is done using a maximum likelihood method implemented in the statistical computing package R, along with its Generalized Simulated Annealing algorithm. The likelihood ratio test and its corresponding p-value are used to compare the statistical significance of adding new GPs to SF models. A production SF (PSF) model for the target, and a costSF (CSF) model for each of the bladder, rectum, and urethra are developed for TRUS-guided HDR-BTtreatment. The difference between the dose value of a plan obtained by IPSA and the one predicted by an SF model is explored. Additionally, to verify if each of the models developed for the TRUS-guided category of the HDR-BT treatment for prostate is universal, we apply it on another category of HDR-BT treatment, in which computed tomography (CT) was used as the imaging modality. So, a different cohort of one hundred clinical CT-guided HDR-BT plans is taken into consideration. A target production SF and three OARs cost SF models are developed for the CT-based plans. Subsequently, the built-in SF models for the TRUS-based and CT-based plans are compared.
This thesis focuses on developing an experience-based quality control (QC) tool, derived from the concept of stochastic frontier (SF) analysis in economics and based on patient-specific geometric knowledge to improve the quality of the high-dose-rate brachytherapy (HDR-BT) treatment for prostate cancer. One hundred clinical HDR prostate BT plans, using the transrectal ultrasound (TRUS) asthe only imaging modality, all treated with a single fraction of 15 Gy, and made using Inverse PlanningSimulated Annealing (IPSA) algorithm, are studied. Also, Oncentra Prostate system is employed as the real-time 3D prostate imaging and treatment planning system. American Brachytherapy Society dose parameter recommendations for target and organs at risk (OARs) were followed. Relationships between all the different geometric parameters (GPs) and the four dosimetric parameters (DPs) V100 of the prostate, V75 of the bladder and rectum, and D10 of the urethra were examined. Geometricinformation of the patients and catheters are considered as different GPs. To find the dominant GPs in a given SF model, monotonic relationships between the GPs and DPs of interest are measured using a nonparametric approach: the Spearman correlation coefficient. Then, to determine the optimal SF model for each of the target production SF, and the OARs cost SF models, brute-force searches are performed. Different SF models including all the possible combinations of the dominant GPs in the SF model under study are optimized. Optimization is done using a maximum likelihood method implemented in the statistical computing package R, along with its Generalized Simulated Annealing algorithm. The likelihood ratio test and its corresponding p-value are used to compare the statistical significance of adding new GPs to SF models. A production SF (PSF) model for the target, and a costSF (CSF) model for each of the bladder, rectum, and urethra are developed for TRUS-guided HDR-BTtreatment. The difference between the dose value of a plan obtained by IPSA and the one predicted by an SF model is explored. Additionally, to verify if each of the models developed for the TRUS-guided category of the HDR-BT treatment for prostate is universal, we apply it on another category of HDR-BT treatment, in which computed tomography (CT) was used as the imaging modality. So, a different cohort of one hundred clinical CT-guided HDR-BT plans is taken into consideration. A target production SF and three OARs cost SF models are developed for the CT-based plans. Subsequently, the built-in SF models for the TRUS-based and CT-based plans are compared.

Mestrado em Ciências Económicas
O Sistema Bancário Português (SBP) tem evoluído ao longo dos últimos vinte anos, não só ao nível do desempenho financeiro e do número de instituições bancárias que o compõe, como ao nível, dos objectivos económicos que pautam os gestores destas empresas. O aumento da concorrência e a globalização estão na base da procura de melhores práticas de mercado e na crescente procura da produtividade e da eficiência das instituições. A utilização do método paramétrico, Stochastic Frontier Analysis (SFA), permitiu estudar a eficiência de vinte e quatro Instituições Financeiras (IF), que operaram em Portugal entre 2000 e 2008. Assume-se como premissa que a eficiência do SBP é dada por factores empresariais, nomeadamente pelo Resultado Líquido das Instituições e não se adopta a Teoria da Intermediação dos Mercados Financeiros. Conclui-se que o total do activo, os recursos captados, o crédito concedido e rácio custos sobre o produto bancário (ou, cost to income), permitem explicar a eficiência técnica do SBP, com nível de significância de 95%. A eficiência técnica ronda os 70%, aumentando apenas quando introduzido o efeito conjunto entre o total do activo e o volume de crédito concedido, das IF em análise, para um nível superior, de aproximadamente 75%. A actividade desempenhada pelas instituições postais francesa, italiana e suiça (La Banque Postal, Banco Posta e Post Finance, respectivamente), são exemplos de outras propostas de valor e de outras formas de eficiência do mercado de retalho bancário. Em Portugal, os CTT detêm um posicionamento singular e reúnem características (como a proximidade com a população, através de uma rede capilar de atendimento e uma marca de confiança) que lhes dão legitimidade para a venda de produtos financeiros, simples e fáceis de perceber pelo mass-market.
Over the past twenty years the Portuguese Bank System has been suffering a huge number of modifications, related with the financial activity performance, economic goals and the number of institutions performing in the market. The best market practices and efficiency are often related with globalization phenomenon and with the increasing of competitiveness among the financial markets. A Stochastic Frontier Model is used to study the efficiency in twenty four Financial Institutions operating in Portugal between 2000 and 2008. It has been assumed that the efficiency of the Portuguese Bank System is related with the economic goals including the Net Profit of the Institutions that are related with total of net income of any Financial Institution, thus it has not been assumed the theory of Financial Intermediation as a basic hypothesis of the model. It follows that the total assets, the funds raised, the credit granted and the cost to income ratio, can explain the technical efficiency of the Portuguese Bank System, with a significant level of 95%. The technical inefficiency is around 70% and the author proposes to assume a "joint effect" between total assets and lending to, in the IF analysis, so that the technical inefficiency increased to a higher level, approximately 75%. The French, Italian and Swedish Postal Operators (La Banque Postal, Banco Posta e Post Finance) are also a benchmarking of efficiency among the Bank Retail Market. CTT is the Portuguese Postal Operator and it holds a unique position and feature characteristics related with its proximity to the population, the density of its branches network and with its strong image in the Portuguese Market. These characteristics are the basic pillars to support the legitimacy and the credibility to sell financials products with no add-ons to the mass-market target.

New Zealand experienced dramatic restructuring programs after the Labor party won the national elections in 1984. Deregulation of price controls, removal of the log export ban, and privatization of public assets were the main shocks to the forest sector. The purpose of this paper is to analyze the impacts of these reforms on wood and paper industry cost, production, and cost efficiency. Unlike previous work, the effects of privatization and deregulation are compared to determine which shock had the most influence on the forest sector. Results show that production decreased, total cost increased, and cost efficiency decreased after deregulation for the sector, and that deregulation was more significant than privatization for the wood and paper sectors. In particular, removal of the log export ban had the greatest impact, while privatization had little effect on industry production and cost. This suggests that countries with comparative advantages in wood processing who implement deregulation or privatization may suffer through a short term period of lower cost efficiency as the economy adjusts to higher input costs in those sectors. In New Zealand's case, the adjustments most likely affecting efficiency have been investments in new technologies, which require time to attain maximum efficiency. The results are contrary to other studies that have predicted increased efficiency as a result of privatization.
Ph. D.

A Work Project, presented as part of the requirements for the Award of a Masters Degree in Economics from the NOVA – School of Business and Economics
This work aims at assessing the Portuguese family health units, whose creation was part of the primary health care reform that began in 2005, in terms of their performance. Family health units are ranked with regard to cost efficiency – stochastic frontier analysis is the econometric technique followed – and the establishment of extreme profiles they compare to is determined through the grades of membership approach. The definition of specific goals for each family health unit to achieve in terms of performance are delivered as the final output of this work, which should allow for improvement of efficiency levels.

A Work Project, presented as part of the requirements for the Award of a Masters Degree in Economics from the NOVA – School of Business and Economics
In a context of economic recession, where resource scarcity follows every manager, efficiency is the only way out. Health Care is no exception. Continuous budgetary cuts from central authorities led to increasing pressures in hospital managers to achieve efficient results. In light of being able to quantify efficiency, this work project has the aim of identifying the best of two frontier based analysis (Stochastic Frontier Analysis and Data Envelopment Analysis) by performing efficiency estimations for a single year using variables from the Portuguese reality, allowing the identification of inefficiency sources. Efficiency scores will be obtained to compare hospitals for efficiency ranks and several efficiency-seeking suggestions will be stated in the end. The scores obtained from the estimations show that some hospitals still have a rough path to endure if they are to achieve economic efficiency. From the analysis we can see that efficient hospitals vary for each model. (8 in SFA [hospitals with a score higher than 0.95] and 17 in DEA). Estimation outputs suggest that changes in hospital size or services provided should occur in order to achieve higher efficiency, which is in light with the presently taken health policies.

A Work Project, presented as part of the requirements for the Award of a Masters Degree in Economics from the NOVA – School of Business and Economics
The purpose of this paper is to study the cost efficiency of multimunicipal systems operating at the bulk level in the Portuguese water sector. We will use Pooled OLS, Fixed Effects and Stochastic Frontier Analysis (SFA) to study the role of structural variables such as water losses, network density, water sources, quality measures, rainfall and topography in explaining the cost differences among those systems. Moreover, using SFA we determine operators’ efficiency scores. We found that inefficiency of operators remained constant over time. The main source of the distance to the cost frontier is a high degree of inefficiency and not exogenous random shocks.

The Asian financial crisis in 1997 98 left a severe impact on Malaysia s economy and banking system. This has forced the Malaysian government to undertake financial restructuring initiatives to restore market and public confidence, and to meet the ongoing challenges associated with market structure, financial innovation and globalisation. Therefore, Bank Negara Malaysia (BNM) introduced a ten-year Financial Sector Master Plan (FSMP) to strengthen domestic banks and the regulatory structure, and to promote the banks efficiency by stimulating a competitive banking industry through financial liberalisation. The crisis for banks in Malaysia and the region has been extensively studied in the past (Sufian, 2010). However, empirical studies of the post-crisis period, and the implementation of the FSMP, remain limited. Hence, a data set of all banks in Malaysia, which covers the period 2000 2011, was employed to examine the effect of the FSMP s initiatives on Malaysian banks efficiency between 2000 and 2011. To measure this efficiency, this study employs both parametric and nonparametric models: namely, stochastic frontier analysis (SFA) and data envelopment analysis (DEA). Economic functions such as, cost-, standard profit- and alternative profit-efficiency were used in a 1-stage SFA model, which includes control variables (e.g. capital adequacy, asset quality and liquidity) and environmental variables (e.g. ownership, size, specialisation, deregulation periods and market structure) in the model specifications. In addition, this study employs SFA as the main measurement method, while the DEA model was used to cross-check consistency (Resti, 1997; Bauer et al., 1998). Both SFA and DEA demonstrated that, in most cases, the consistency was moderate. The level of cost efficiency of Malaysian banks worsened over the years 2000 2011, with average cost efficiency during this period was at 76.5%. Despite the various liberalisation measures introduced to the banking industry particularly during the three phases of the FSMP; 2000 2003; 2004 2007; 2008 2011 cost efficiency trended downward, due to the effects of consolidation by domestic banks, deregulation of interest rates, the introduction of foreign Islamic banks, and the global credit crisis. Banks in Malaysia were forced to adjust their inputs and outputs to the rapid changes in the banking industry, which might have made a negative impact on cost efficiency. On the other hand, the banks demonstrated a steadily increasing profit efficiency trend, which fluctuated with the introduction of interest rate liberalisation (early second phase of the FSMP (i.e. 2004)) and during the global credit crisis (early third phase of the FSMP (i.e. 2008)). The average profit efficiency for 2000 2011 was 93.3%. The profit efficiency exhibited an increasing trend in the first (2000-2003) and second (2004-2007) phases of the FSMP, suggesting that the effect of consolidation by domestic banks had resulted in higher market concentration and greater market power among the remaining banks. However, the profit efficiency average scores fell in 2004, 2008 and 2011. This is attributed to the deregulation of interest rates, the deleveraging of the inflow of foreign funds, and the rapid increase in policy interest rates. At a more granular level, domestic banks were found to be more cost efficient, but marginally less profit efficient, when compared to foreign banks. In terms of bank specialisation, conventional banks were more cost- and profit-efficient than Islamic banks. With regard to economies of scale, the majority of Malaysian banks revealed scale economies, illustrated by a U-shape, with medium-sized banks being more scale efficient than small and large banks. These results suggest that, to enhance Malaysian banks efficiency, the government must maintain competitive pressure on the large domestic banks that were consolidated during the first phase of the FSMP (2000-2003). Policymakers may want to further open up banking markets, improve risk management and governance, encourage financial innovation, and support expansion of smaller banks. The implementation of deregulation initiatives during periods of uncertainty (e.g. the global credit crisis) have also resulted in decreasing trend of cost and profit efficiency. Hence, monitoring initiatives, using tools such as frontier measurement is important for regulator s macro- and micro-prudential surveillance.

Since the open door policy was embarked upon in 1979, China s banking sector has undergone gradual but notable reforms. A key objective of the reforms implemented by the Chinese government is to build an effective, competitive and stable banking system in order to improve its efficiency and reliability. This study employs both parametric stochastic frontier analysis (SFA) and non-parametric data envelopment analysis (DEA) methods to assess and evaluate the cost efficiency of Chinese banks over the period from 1994 until 2007, a period characterised by far-reaching changes brought about by the banking reforms. To this end, we first compare a number of specifications of stochastic cost frontier models to determine the preferred frontier model which are adopted in our efficiency analysis. The preferred model specification for our sample is the one stage SFA model that includes the traditional input prices, the outputs and the control variables (that is, equity, non-performing loans and the time trend) in the cost frontier and the environmental variables (that is, ownership structure, size, deregulation, market structure and market discipline) in the inefficiency term. Moreover, we also employ two cost DEA models (traditional DEA and New DEA) as a complement to the preferred SFA model for methodological cross-checking purposes. Similar to the previous empirical literature, we find that in most cases only moderate consistency across the different techniques. The cost efficiency of Chinese banks is found to be 91% on average, based on our SFA model, over the period from 1994 until 2007. Based on the results of the DEA and New DEA models, the average cost efficiency for Chinese banks over the sample period is about 89% and 87%, respectively. We find that Chinese banking efficiency has deteriorated after China s admission to the WTO, suggesting that the significant external environmental changes which arose from China s WTO entry may have had a negative impact on its banking efficiency. In addition, we find that the majority of Chinese banks reveal scale inefficiencies and as asset size increases, banks tend to pass from increasing, to constant, and then to decreasing returns to scale. Our findings also show that both state-owned banks and foreign banks are more efficient than domestic private banks and larger banks tend to be relatively more efficient than smaller banks. These and other results suggest that in order to enhance Chinese banking efficiency, the government needs to continue with the banking reform process and in particular, to open up banking markets, to improve risk management and corporate governance in Chinese banks and to encourage the expansion of banks.

This thesis analyzes the efficiency structure of Turkish agriculture in farm household level by using various models of stochastic frontier analysis. A household level survey conducted in 2002 and 2004 is used in the analysis. Firstly, an efficient production frontier is estimated by a panel data models. By using these estimates, relative importance of production factors and their interaction with various farm specific factors are inspected. The parameters of production frontier show that agricultural production is crucially dependant on land and there is an excessive employment of labor in Turkish agriculture. Secondly, the efficiency scores are estimated at farm household level. The results are reported according to NUTS-II regional classification and many other farm specific characteristics. The western parts of the country are found to be relatively more efficient and there is a high deviation in mean efficiencies of different regions. There is an increase in mean efficiencies of all regions from 2002 to 2004. Besides, crop patterns, farm size, education level of household chief and irrigation are found to be effective on efficiency.

This paper provides simulation evidence concerning some statistical properties of two different approaches to technical efficiency estimation for multiple-output production under noisy conditions: The Ray Frontier Approach (RFA) from Löthgren (1997) DEA+ proposed in Gstach (1996). RFA, unlike earlier approaches in the realm of stochastic frontier analysis, is capable of efficiency estimation in the case of multiple outputs as well and lends itself for comparison with DEA+. Several settings with varying sample sizes, noise to signal ratios and mean inefficiencies are investigated. (author's abstract)
Series: Department of Economics Working Paper Series

The thesis examines technical efficiency using frontier efficiency estimation techniques from parametric and non-parametric approaches. Five different frontier efficiency estimation techniques are considered which are SFA, DFA, DEA-CCR, DEA-BCC and DEA-RAM. These techniques are then used on an artificially generated panel dataset using a two-input two-output production function framework based on characteristics of German life-insurers. The key contribution of the thesis is firstly, a study that uses simulated panel dataset to estimate frontier efficiency techniques and secondly, a research framework that compares multiple frontier efficiency techniques across parametric and non-parametric approaches in the context of simulated panel data. The findings suggest that, as opposed to previous studies, parametric and non-parametric approaches can both generate comparable technical efficiency scores with simulated data. Moreover, techniques from parametric approaches, i.e. SFA and DFA are consistent with each other whereas the same applies to non-parametric approaches, i.e. DEA models. The research study also discusses some important theoretical and methodological implication of the findings and suggests some ways whereby future research can enable to overcome some of the restrictions associated with current approaches.

This thesis compares different approaches to estimating budgets for Kuhn-Tucker (KT) demand systems, more specifically for the multiple discrete-continuous extreme value (MDCEV) model. The approaches tested include: (1) The log-linear regression approach (2) The stochastic frontier regression approach, and (3) arbitrarily assumed budgets that are not necessarily modeled as a function of decision maker characteristics and choice-environment characteristics. The log-linear regression approach has been used in the literature to model the observed total expenditure as way of estimating budgets for the MDCEV models. This approach allows the total expenditure to depend on the characteristics of the choice-maker and the choice environment. However, this approach does not offer an easy way to allow the total expenditure to change due to changes in choice alternative-specific attributes, but only allows a reallocation of the observed total expenditure among the different choice alternatives. To address this issue, we propose the stochastic frontier regression approach. The approach is useful when the underlying budgets driving a choice situation are unobserved, but only the expenditures on the choice alternatives of interest are observed. The approach is based on the notion that consumers operate under latent budgets that can be conceived (and modeled using stochastic frontier regression) as the maximum possible expenditure they are willing to incur. To compare the efficacy of the above-mentioned approaches, we performed two empirical assessments: (1) The analysis of out-of-home activity participation and time-use (with a budget on the total time available for out-of-home activities) for a sample of non-working adults in Florida, and (2) The analysis of household vehicle type/vintage holdings and usage (with a budget on the total annual mileage) for a sample of households in Florida. A comparison of the MDCEV model predictions (based on budgets from the above mentioned approaches) demonstrates that the log-linear regression approach and the stochastic frontier approach performed better than arbitrarily assumed budgets approaches. This is because both approaches consider heterogeneity in budgets due to socio-demographics and other explanatory factors rather than arbitrarily imposing uniform budgets on all consumers. Between the log-linear regression and the stochastic frontier regression approaches, the log-linear regression approach resulted in better predictions (vis-à-vis the observed distributions of the discrete-continuous choices) from the MDCEV model. However, policy simulations suggest that the stochastic frontier approach allows the total expenditures to either increase or decrease as a result of changes in alternative-specific attributes. While the log-linear regression approach allows the total expenditures to change as a result of changes in relevant socio-demographic and choice-environment characteristics, it does not allow the total expenditures to change as a result of changes in alternative-specific attributes.

Evaluations of the Higher Education Sector are receiving increased attention, due to the rising expenditures and the absence of efficiency enhancing market pressure. To what extent universities are able to eliminate inefficiency is a question that has only partially been answered. This paper argues that heterogeneity among universities as well as persistent inefficiency hinder the institutions to achieve full efficiency - at least in the short run. Two standard and one novel specification of the Stochastic Frontier Analysis are applied to a new, comprehensive set of panel data to show how the standard efficiency evaluation changes when both aspects are taken into account. It is the first time that the idea of persistent inefficiency is considered in the analysis of the German Higher Education Sector. The comparison reveals that the disregard of heterogeneity distorts the estimation results towards lower efficiency values. The newly introduced specification improves the accuracy of the heterogeneity assumption and exposes that inefficiency tends to be long term and persistent rather than short term and residual. This implies that increasing efficiency requires a comprehensive change of the university structure.

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A reforma agrária permanece um tema atual em função das tensões provocadas pela concentração de terras e pela falta de alternativas de ocupação para parte da população que ainda vive no meio rural. Ao transferir terras improdutivas para famílias com potencial produtivo, a reforma agrária pode aumentar a eficiência econômica. O modelo de reforma agrária brasileiro, baseia-se no assentamento de famílias sem terra, em terras devolutas ou desapropriadas de imóveis improdutivos. Os programas de acesso à terra via mercado são instrumentos complementares, disponibilizam crédito para grupos de produtores comprarem a propriedade no mercado fundiário. Portanto, espera-se que estes mecanismos produzam resultados distintos sobre a alocação de recursos e eficiência produtiva. O objetivo deste trabalho foi medir a eficiência de produção relativa entre os assentados segundo o mecanismo de acesso à terra. A análise de eficiência produtiva foi realizada utilizando-se um modelo de fronteira estocástica de produção sob a forma funcional Cobb-Douglas. Os dados são representativos para o conjunto dos estados: Bahia, Ceará, Maranhão, Pernambuco e Norte de Minas Gerais. A eficiência média estimada foi de 0,3163, sendo 0,3678 para os assentados por desapropriação e 0,3537 para os beneficiários com acesso à terra via mercado. A produção apresentou rendimentos decrescentes em função dos fatores de produção, com maior elasticidade parcial para terra. Os resultados não indicaram evidências de que o acesso à terra via mercado contribuísse para a eficiência dos assentados. Contribuíram positivamente para eficiência, as fontes: trabalho externo, trabalho coletivo, localização em municípios com solos de qualidade superior, localização nos estados do Maranhão e Ceará, idade do chefe da família, o cultivo irrigado e emprego de tração mecânica nas atividades produtivas
Land reform remains a current theme considering the tensions provoked by the concentration of lands and the lack of alternatives of employment for the population who live in rural areas. Land reform can improve the economic efficiency level when the unproductive lands are transferred to families with productive potential. The model of Brazilian land reform is based on settlements of families without land, in unoccupied public lands, or expropriation of unproductive estates. The market assisted land reform programs are considered complementary instruments of land reform. They are used to provide credit for land purchase by groups of landless farmers directly from the land market. The aim of this research was to measure the profit efficiency, considering two different mechanisms of land access. The analysis of profit efficiency was performed using the Stochastic Frontier Analysis. The frontier of production was estimated based on Cobb-Douglas production function. The data set represents the states: Bahia, Ceará, Maranhão, Pernambuco and the north region of Minas Gerais. The overall efficiency estimates were 0.3163. The efficiency estimates were 0.3678 for the farmers assigned by expropriation, and 0.3678 for the farmers with market land access. The production showed decreasing gains with the major partial elasticity for land. The positive efficiency effect sources are: farm labor, collective labor, location in superior soil class county areas, location in Maranhão and Ceará states, age of head of household, crops with irrigation or flood, and use of machinery. The negative efficiency effect sources are: outer-incomes and family consumption of its own production. There was no evidence that the farmers assigned by market assisted land reform developed more efficiency. On the other hand, it is not correct to conclude that farmers assigned by land expropriation developed better profit efficiency level

This dissertation examines multiple state and local expenditure categories in the United States to expand understanding of fiscal federalism and spatial interactions among governments. First, the author investigates the relationship between police expenditures and crime rates from a spatial perspective. Both police expenditures and crime rates in one state are found to exhibit a similar pattern to that in neighboring states. Spatial correlation is also detected between police expenditures and crime rates. As police of neighbors in fact deter crime at home, there are positive externalities present among the states. Second, the author conducts new tests on the Leviathan hypothesis, i.e., more competition, smaller government. While cost efficiency is used in place of government size to capture the idea that fiscal decentralization reduces wasteful expenditures, spatial interaction is taken as another measure for decentralization. The hypothesis is supported by some evidence from total, police, highway, and welfare expenditures.

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
O objetivo deste estudo é medir o crescimento da produtividade total dos fatores (PTF) segundo o tamanho dos estabelecimentos agropecuários na região Sudeste entre os Censos Agropecuários de 1985, 1995/96 e 2006, assim como decompor a mudança da PTF em dois componentes, mudança tecnológica e mudança na eficiência técnica. Este objetivo está fundamentado nas hipóteses de que exista heterogeneidade no crescimento da PTF segundo o tamanho dos estabelecimentos, e que distintas fontes expliquem essa heterogeneidade. A metodologia está baseada na análise de fronteira estocástica de produção. Os dados são representativos para os municípios da macrorregião, considerando cinco classes de área: 0-5 ha, 5-20 ha, 20-100 ha, 100-500 ha, 500 e mais ha. Observou-se crescimento da PTF para a região Sudeste. A decomposição deste crescimento apontou a mudança tecnológica como a principal fonte de ganho de produtividade. A mudança na eficiência técnica foi negativa. O crescimento da PTF entre os tamanhos de estabelecimentos e entre as unidades da federação da região Sudeste foi heterogêneo. Os maiores estabelecimentos, 100-500 ha e 500 e mais ha, alcançaram maior crescimento da PTF do que os estabelecimentos das três primeiras classes de área, 0-5 ha, 5-20 ha e 20-100 ha. Para as unidades da federação, notou-se que a PTF do estabelecimento de São Paulo cresceu relativamente mais rápido.
The aim of this paper is to measure the total factor productivity (TFP) growth by farm size in Southeast, from the 1985, 1995/96 and 2006 Agricultural Census, as well as to decompose TFP change into two components, technical change and technical efficiency change. This aim is based on the hypothesis that there is heterogeneity in TFP growth by farm size, and that different sources explain such heterogeneity. The methodology is based on stochastic frontier analysis. The data are aggregated at the municipality level into five size classes: 0-5 ha, 5-20 ha, ha 20-100, 100-500 ha, greater than 500 ha. It was observed productivity growth in Southeast. The decomposition of this growth showed to technical change as the main source of productivity gain. The technical efficiency change was negative. This growth was heterogeneous among size class and among states of the Southeast region. The largest farms, 100-500 ha and greater than 500 ha, achieved higher TFP growth than the first three size classes, 0-5 ha, 5-20 ha and 20-100 ha. Among states, it was noticed that the TFP in São Paulo farm grew relatively faster.

This thesis adopts a new operational method to measure and investigate the relationship among cost efficiency, market competition and profitability in major Asian economies by using an unbalanced panel data sample of 278 commercial banks during the financial upheaval period of 2005-2012 before and after the global financial crisis. Firstly, we estimate the cost efficiency by employing different stochastic frontier analysis (SFA) models, which include the equity capital to indicate loss-absorbing capacity and risk preference and cross-country differences to be additional environmental variables. It is generally agreed that cross-country differences influence the frontier technology in the international comparison of banks performance. In this case, we implement the international comparison under SFA models with and without incorporating these cross-country heterogeneities. And the empirical results suggest that cross-country differences are significant sources to measure banks cost efficiency and evaluate banks performance. Secondly, we measure the market competition by investigating a range of approaches: the traditional Structure-Conduct-Performance approach, Lerner index, and new empirical industrial organization Panzar-Rosse approach. And we find that the SCP-Lerner approach may fail to identify the strength of competition and may not always unambiguously distinguish between the market power and the efficiency explanations of market concentration. Finally, following the approach of Boone, we measure the intensity of competition in two ways: the profit elasticity and the relative profit difference (calculated by cost efficiency score and shadow return on equity capital). Then we implement a quadratic quantile regression to compute the integral areas and standard errors for the Boone visual test and Wald test to reflect the relative intensity of competition for different competitive regimes over time. Our findings show that competition of banking industries become more intense in 9 Asian economies in the wake of the financial crisis and that two advanced economies (Singapore and Taiwan Province of China) and two remarkable emerging economies (China and India) play the significantly leading role in this intensifying competition process.

Doutoramento em Economia
Neste trabalho, através de uma meta-análise, pretende-se integrar os resultados obtidos nos estudos sobre a eficiência, realizados no sector energético, e analisar se as decisões metodológicas influenciam os valores de eficiência estimados. Os dados são constituídos por 162 modelos reportados em 63 artigos científicos que analisaram empiricamente o nível de eficiência no sector energético no período de 1979 a 2013. Através de um modelo de meta- regressão, a investigação focaliza-se em tentar perceber que efeitos podem ter as diferentes especificações dos modelos nos valores estimados para a eficiência. Analisa-se o impacto que as variáveis - revista no qual o estudo é publicado, ano de publicação, método paramétrico versus não paramétrico, tipo de função, forma funcional aplicada, orientação input versus output, distribuição do erro, efeitos aleatórios versus efeitos fixos, dimensão da amostra, tipo de dados, ano a que se referem os dados e número de variáveis output incluídas - podem ter no nível de eficiência estimado para as unidades de produção e distribuição energética. Os resultados parecem demonstrar que o ano de publicação do artigo, opção pela função custo, a forma funcional translog, a distribuição semi-normal para o termo de erro, dados de painel e o número de variáveis output têm um impacto negativo no cálculo da estimativa da eficiência. Por outro lado, a opção pelo modelo de efeitos aleatórios tem um impacto positivo. Relativamente à média dos anos de observação e dimensão da amostra, os resultados demonstram que não existe qualquer efeito relevante. Existe evidência estatística, a um nível de significância de 5%, para afirmar que as variáveis Energy Economics journal, modelos paramétricos, orientação input e rendimentos variáveis à escala produzem efeito positivo na estimativa da eficiência. Por último, o modelo especificado neste trabalho e os resultados obtidos permitem acomodar outras variáveis que tenham como objectivo o aprofundamento e futuros desenvolvimentos deste trabalho.
In this paper, through a meta-analysis, we intend to integrate the results obtained in studies conducted on the efficiency in the energy sector and try to understand if indeed the methodological decisions influence the efficiency values estimated. The data consist of 162 models reported in 63 scientific articles that empirically analyzed the level of efficiency in the energy sector from 1979 to 2013. Through a meta-regression model, the research focuses on trying to understand what effects may have the different specifications of the models in the estimated values for efficiency. We analyze the impact of variables - journal in which the study is published, year of publication, parametric versus nonparametric method, type of function, functional form applied, input versus output orientation, error distribution, random effects versus fixed effects, sample size, data type, the year to which they relate data and number of output variables - can have on the estimated level of efficiency for units of energy production and distribution. The results demonstrate that the year of publication of the article, the option cost function, the translog functional form, the half-normal distribution for the error term, panel data and the number of output variables have a negative impact on the calculation of the estimate value of efficiency. Moreover, the choice of the random effects model has a positive impact. For the average of years of observation and sample size, the results demonstrate that there is no significant effect. There is statistical evidence, a 5% significance level, for asserting that the variables Journal Energy Economics, parametric method, input orientation and variables returns to scale produce positive effect on the estimation of efficiency. Finally the model specified in this study and the results indicate the possibility of integrating other variables that aim to deepen this work and future developments of this work are indicated.

Orientador: Maristela Simões do Carmo
Banca: Elias José Simon
Banca: José Maria Ferreira J.da Silveira
Banca: Liciana Vaz de Arruda Silveira
Banca: Paulo André de Oliveira
Resumo: A reforma agrária permanece um tema atual em função das tensões provocadas pela concentração de terras e pela falta de alternativas de ocupação para parte da população que ainda vive no meio rural. Ao transferir terras improdutivas para famílias com potencial produtivo, a reforma agrária pode aumentar a eficiência econômica. O modelo de reforma agrária brasileiro, baseia-se no assentamento de famílias sem terra, em terras devolutas ou desapropriadas de imóveis improdutivos. Os programas de acesso à terra via mercado são instrumentos complementares, disponibilizam crédito para grupos de produtores comprarem a propriedade no mercado fundiário. Portanto, espera-se que estes mecanismos produzam resultados distintos sobre a alocação de recursos e eficiência produtiva. O objetivo deste trabalho foi medir a eficiência de produção relativa entre os assentados segundo o mecanismo de acesso à terra. A análise de eficiência produtiva foi realizada utilizando-se um modelo de fronteira estocástica de produção sob a forma funcional Cobb-Douglas. Os dados são representativos para o conjunto dos estados: Bahia, Ceará, Maranhão, Pernambuco e Norte de Minas Gerais. A eficiência média estimada foi de 0,3163, sendo 0,3678 para os assentados por desapropriação e 0,3537 para os beneficiários com acesso à terra via mercado. A produção apresentou rendimentos decrescentes em função dos fatores de produção, com maior elasticidade parcial para terra. Os resultados não indicaram evidências de que o acesso à terra via mercado contribuísse para a eficiência dos assentados. Contribuíram positivamente para eficiência, as fontes: trabalho externo, trabalho coletivo, localização em municípios com solos de qualidade superior, localização nos estados do Maranhão e Ceará, idade do chefe da família, o cultivo irrigado e emprego de tração mecânica nas atividades produtivas
Abstract: Land reform remains a current theme considering the tensions provoked by the concentration of lands and the lack of alternatives of employment for the population who live in rural areas. Land reform can improve the economic efficiency level when the unproductive lands are transferred to families with productive potential. The model of Brazilian land reform is based on settlements of families without land, in unoccupied public lands, or expropriation of unproductive estates. The market assisted land reform programs are considered complementary instruments of land reform. They are used to provide credit for land purchase by groups of landless farmers directly from the land market. The aim of this research was to measure the profit efficiency, considering two different mechanisms of land access. The analysis of profit efficiency was performed using the Stochastic Frontier Analysis. The frontier of production was estimated based on Cobb-Douglas production function. The data set represents the states: Bahia, Ceará, Maranhão, Pernambuco and the north region of Minas Gerais. The overall efficiency estimates were 0.3163. The efficiency estimates were 0.3678 for the farmers assigned by expropriation, and 0.3678 for the farmers with market land access. The production showed decreasing gains with the major partial elasticity for land. The positive efficiency effect sources are: farm labor, collective labor, location in superior soil class county areas, location in Maranhão and Ceará states, age of head of household, crops with irrigation or flood, and use of machinery. The negative efficiency effect sources are: outer-incomes and family consumption of its own production. There was no evidence that the farmers assigned by market assisted land reform developed more efficiency. On the other hand, it is not correct to conclude that farmers assigned by land expropriation developed better profit efficiency level
Doutor

Innovation efficiency is a key factor influencing the position of high-tech industries in the global value chain. Through stochastic frontier analysis, innovation efficiency of China's high-tech industry from 2000 to 2016 was estimated and analyzed. Through five random frontier analysis models, innovation efficiency of new product sales revenue and number of patent applications are analyzed. Results show that the overall level of innovation efficiency in China's high-tech industry is not high. Government subsidies for innovation have a positive impact on the R&D results of new product income from China’s high-tech industry, but have a negative impact on the number of patent applications. Scale of enterprise, degree of openness of enterprise, quality of the labor force and export delivery have a positive impact on innovation efficiency of China's high-tech industry. R&D capital stock and R&D human capital stock have a positive effect on high-tech industry innovation. In high-tech industry's transition from patents to new products, there will be a low conversion rate. Results of economic analysis can help the government to make the basis for management decisions. Conclusion of innovation performance analysis provides practical normative guidance for these high-tech industries.

This dissertation is composed of three essays; the first two examine the decisionmaking of potato producing households in Bolivia and the third examines well-being changes among Zimbabwe households. The first essay entitled “The role of risk mitigation in production efficiency: A case study of potato cultivation in the Bolivian Andes” estimates the costs of self-managing environmental risk through activity and environmental diversification. Risk management has the potential to reduce income variability but at the cost of increasing production inefficiency, which we measure employing a stochastic production frontier. Among variables capturing environmental diversification, discontinuity between fields has the most detrimental effect on production efficiency. Activity diversification, measured by the ratio of potato to total crop revenue, has a stronger impact on inefficiency and yield losses than any of the environmental diversification variables. The second essay entitled “Determinants of market participation decisions and marketing choices in Bolivia” examines three decisions related to potato market participation: market entry, volume sold, and market choice. The first two are analyzed using a Heckman selection model. Results indicate that isolation, measured by population density and distance to markets, negatively impacts market entry. The most important determinant of quantity sold is land holding. Market choices are judged according to second-order stochastic dominance (SOSD). Market choices meeting the SOSD criterion are referred to as optimal marketing strategies as they have the higher expected payoff for a minimal income variance. Results suggest that the probability of selecting an optimal marketing strategy increases with quantity sold, access to market information, and access to liquidity while it decreases with distance to markets. The third essay entitled “A profile of changes in well-being in Zimbabwe, 2001- 2007/8, using an asset index methodology” shows that it is possible to examine intertemporal and spatial changes in well-being in the absence of consumption expenditures data by using an asset index. The asset index was constructed using Polychoric Principal Component Analysis. Results indicate that poverty and extremely poverty grew significantly in rural Zimbabwe while in urban areas, poverty diminished and extreme poverty grew.
Ph. D.
LTRA-7 (Pathways to CAPS in the Andes)

This paper offers to measure efficiency of banks in Sub Saharan Africa and its determining input andout put factors on two fonts. At this purpose, we applied the first font; Data Envelopment Analysis(DEA) for assessing efficiency level. The actual and target level of inputs/outputs to foster efficiencyare shown in the results. Secondly, the banks ratio analysis measuring banks performance throughreturns volatility for each bank, asset utilization and provision for bad and doubtful debts over thestudy period are all used as tools for this analysis. Our results suggest that Sub Saharan AfricanBanks are about 98.35% efficient. We are aware that the level of efficiency could be subject to up anddown swing if environmental factors influencing banks efficiency where taken into consideration.Finally, our result (DEA) is more sensitive to loans, other liabilities, other non interest expense,securities and deposit.

Classificação JEL: I18, C02
Os hospitais são unidades complexas que produzem múltiplos outputs através da utilização de múltiplos inputs (Fare et al., 1994b). A par da sua complexidade, colocam-se questões relevantes relativas ao seu funcionamento, à sua eficiência pelos recursos envolvidos no seu funcionamento. Estima-se que cerca de metade dos recursos aplicados no sector da saúde dizem respeito ao funcionamento dos hospitais A conjugação desta situação, com a necessidade de combater as despesas da administração pública, esteve na base da onda reformista conhecida por New Public Management (NPM). A NPM teve origem, e conheceu grande impulso, nos países anglo-saxónico, nomeadamente, no Reino Unido. Nesta onda reformista que se assistiu, o sector da saúde foi onde, provavelmente, maiores alterações foram ensaiadas, como por exemplo a criação dos chamados quase-mercados ou mercado interno da saúde. Neste contexto, parte significativa dos hospitais do National Health Service (NHS) foram transformados em hospitais trusts. Em Portugal, na linha deste movimento reformista, foram ensaiadas algumas experiências no sector hospitalar, em particular, a empresarialização de 34 hospitais do SNS que deram origem a 31 hospitais SA (sociedades anónimas). Como principais conclusões da investigação, refira-se que, em consequência da criação dos hospitais SA, registou-se melhoria da fronteira de eficiência técnica da indústria hospitalar, embora o deslocamento da fronteira não seja muito significativo, e os hospitais SPA evidenciam níveis de eficiência técnica ligeiramente mais elevados do que os hospitais SA
Hospitals are complex bodies which produce multiple outputs through the utilisation of multiple inputs (Fare et al., 1994b). Besides complexity, many relevant issues are raised in regard to its operation and efficiency is one of them. It is estimated that half of the resources assigned to the health sector are allocated to hospitals operations. In Portugal, reforms in the public sector have started in the decade of 90’s of the last century and great efforts have been made to fight back the excessive expenditure in the health sector. Under this movement, some experiences in hospital management have been carried out, in particular, the privatisation of the management system of 34 hospitals of the Portuguese National Health System by converting them into 31 corporations running the hospital business. The study we have conducted concerns the economic efficiency of hospitals and our analysis is based on the concept of the efficiency frontier (Farrell, 1957). For achieving this objective we have explored two possible methodologies, the parametric approach which is the econometric one, and the non-parametric approach, the data envelopment analysis. As main conclusions of our research, the newly established hospital corporations helped to improve the efficiency frontier of the entire hospital industry, notwithstanding public hospitals could show higher technical efficiency scores than those that were transformed into corporations.

博士
國立交通大學
管理科學系所
107
Since energy is an indispensable resource for economic development, effective energy usage provides a solution for solving the conflict among economic development, energy conservation, and environmental sustainability. Using the stochastic frontier analysis (SFA) model, this research measures total-factor energy efficiency (TFEE) and disaggregate input efficiency for 10 countries across the Baltic Sea from 2004 to 2014. Real capital, labor, energy use, and carbon dioxide (CO2) are input variables, real gross domestic product (GDP) is the output variable, and renewable energy consumption and urban population are the environmental variables. The results provide not only the TFEE scores, in which statistical noise is considered, but also the determinants of inefficiency, noting the following. (i) Norway, Sweden, Finland, and Latvia perform better with respect to energy efficiency than other countries in the Baltic Sea Region. (ii) Interestingly, the average energy use efficiency scores from 2004 to 2014 in the 10 Baltic countries exhibit a gradual upward trend except for 2009. (iii) When estimating disaggregate energy efficiency, higher renewable energy consumption and urban population correspond to higher TFEE scores. (iv) When estimating disaggregate CO2 emissions, higher renewable energy consumption and urban population correspond to higher TFEE scores.

碩士
國立臺灣大學
經濟學研究所
107
In this paper, we propose a new stochastic frontier model under a sharp regression discontinuity design to measure how treatment affects both the frontier function and the level of inefficiency at the cutoff. We assume that the frontier function and the conditional expectation of nonnegative inefficiency of the potential outome variable are parametrically specified at the cutoff of the running variable. Under suitable conditions, we show the identification of the corresponding parameters and the conditional average treatment effect. Then we propose a local nonlinear least square estimator with the semiparameter form with respect to the running variable at the cutoff that is different from nonparametric maximum likelihood methods. We show the consistency and asymptotics normal distribution of the estimator of parameters and asymptotics normal distribution of the estimator of the conditional average treatment effect at the cutoff.

Tese de mestrado em Estatística, apresentada à Universidade de Lisboa, através da Faculdade de Ciências, 2011
Portugal é um país costeiro com cerca de 1200 km de costa, fazendo da pesca uma das actividades mais importantes, económica e culturalmente. Uma das espécies mais pescadas em Portugal é o peixe-espada preto, fazendo desta espécie uma das mais estudadas devido ao seu impacto socioeconómico. Desde o século XVII que na Madeira, o peixe-espada preto é pescado, mas só em 1983 foi iniciada esta pesca em Portugal continental, sendo Sesimbra a principal zona pesqueira. Assim sendo, foi de Sesimbra que vieram grande parte dos dados que foram usados neste trabalho. A regulação e a gestão da actividade pesqueira continuam a ser um dos maiores desafios, sendo assim essencial a avaliação do estado dos recursos explorados (neste caso o peixe-espada preto). Tal avaliação é vital para procurar medidas que garantam a sustentabilidade do recurso e da pesca. Um dos índices de abundância mais utilizados ´e o CPUE (captura-por-unidade-esforço), que é definido como a razão entre o total capturado e o total de esforço aplicado nessa mesma captura. Apesar do seu frequente uso é sabido que o CPUE é influenciado por outros factores para além do nível de abundância. Assim, para minimizar essa influência, o CPUE é estandardizado de forma a diminuir ou até remover os eventuais factores de confusão. Para tal foram aplicados Modelos Lineares Generalizados (GLM), que não são mais do que uma generalização dos Modelos Lineares. Essa generalização permite que a distribuição da variável resposta pertença à família exponencial (para além da Normal), e permite que a função de ligação entre a variável resposta e as variáveis explicativas seja uma função monótona diferenciável. Para estimar tal índice, a fonte de dados é frequentemente o diário de bordo. Na União Europeia e desde a introdução de Política Comum das Pescas, que reúne várias medidas para garantir a sustentabilidade da pesca europeia, é obrigatório registar toda a viagem desde a partida do porto até ao desembarque. Além disso, dado que não há dados independentes da pesca, ou seja, não há estudos dirigidos para a recolha de dados através de amostragem, a estimação deste tipo de índices acaba por depender quase exclusivamente dos diários de bordo. Assim acabam por assumir uma importância vital quer na monitorização quer na regulamentação da actividade pesqueira. O preenchimento destes diários de bordo é feito pelos mestres das embarcações no mar e é posteriormente introduzido numa base de dados pela Direcção Geral das Pescas e da Aquicultura. Contudo há erros ou más interpretações no preenchimento dos diários de bordo que podem de alguma forma enviesar quer os resultados quer as conclusões de estudos neles baseados. Além de que os dados retirados dos diários de bordo reflectem sempre imensa variedade nas espécies capturadas além da espécie alvo. Apesar disto, os diários de bordo são a fonte de dados de vários trabalhos que visam estimar níveis de abundância. Desta forma, é necessário medir e quantificar o impacto que uma base de dados menos cuidada pode ter na qualidade e na veracidade dos trabalhos que nela se baseiam. É este objectivo que visa a primeira parte deste trabalho (chapter 2), usando os dados contidos nos diários de bordo da frota que opera em Sesimbra e que tem como espécie alvo o peixe-espada preto. Os factores e variáveis relevantes para a estimação do CPUE também foram identificadas, assim como a respectiva influência. Desta primeira parte do trabalho resultou uma análise extensiva e detalhada dos diários de bordo, permitindo identificar os erros e até nalguns casos corrigi-los através do conhecimento de trabalho anteriores e da comunidade pesqueira de Sesimbra. Análise essa que recorreu a várias ferramentas estatísticas (p.e. Análise de Clusters, Tabelas de Contingência, e Testes de Significância) e que foi suportada por análise gráfica (p.e. Scatter-plots, QQ-plots e Histogramas). Foi possível então comparar os resultados obtidos entre duas bases de dados, uma mais cuidada do que outra no que toca ao registo de observações. Diferença essa que foi bem visível na percentagem de explicação do modelo, onde houve um decréscimo de 20 pontos percentuais. Inspirada nestes resultados, surgiu a ideia de aplicar outra abordagem e usar outra fonte de dados que não os diários de bordo. A sustentabilidade do recurso, para além de outros factores, passa pela utilização eficiente de recursos de modo a garantir a renovação constante do peixe para níveis óptimos. Tal eficiência só pode ser atingida minimizando o desperdício dos recursos gastos durante a actividade pesqueira e maximizando o proveito socioeconómico dessa mesma actividade. Apesar deste conhecimento geral, nem todos os produtores (neste caso embarcações) são bem sucedidos em atingir níveis satisfatórios de eficiência. Existem várias abordagens para estimar e avaliar a eficiência duma actividade económica, em particular Análise de Fronteiras Estocásticas (SFA), que combina dois campos da ciência, a Estatística e a Economia. Esta metodologia foi desenvolvida por Aigner and Schmidt [1977] e por Meeusen and van den Broeck [1977], e tem sido aplicada em vários campos e sido objecto de várias pesquisas, sendo até considerada por alguns autores como a melhor abordagem na presença da ineficiência. Dentro desta metodologia podem ser consideradas três tipos de eficiência: T´ecnica (Technical Efficiency), Custo (Cost Efficiency) e Lucro (Profit Efficiency). Neste estudo apenas foi estimada a Eficiência Técnica que pode ser descrita como a habilidade de, dado um resultado fixo (output), minimizar a quantidade de variáveis (inputs) necessárias para obter tal resultado, ou a habilidade de maximizar o resultado obtido de um conjunto de variáveis fixas. O conceito ´e simples e até tem havido um crescente interesse em aplicar esta metodologia à actividade pesqueira, no entanto são poucos os trabalhos realizados sobre este tema, e os poucos que há são estudados duma perspectiva económica e não estatística. Assim este trabalho vem, de alguma forma, tentar preencher esse vazio realizando esta abordagem do ponto de vista estatístico. A segunda parte deste trabalho (chapter 3) tem então o propósito de avaliar esta abordagem teoricamente e verificar se é na prática uma ferramenta útil e de fácil aplicação. Assim, dentro deste estudo, a eficiência técnica de todas as embarcações que compõem a frota de peixe-espada preto de Sesimbra foram estimadas. Para tal foram recolhidos dados através de inquéritos aos envolvidos nesta actividade, sendo obtido dados relativos aos anos de 2009 e 2010. Dos resultados foi possível identificar diferenças entre várias abordagens e modelos, avaliar a evolução da eficiência no tempo, procurando tendência e/ou sazonalidade e finalmente verificar que a pesca do peixe-espada preto desenvolvida em Sesimbra pode ser considerada eficiente.
In fisheries world the knowledge of the state of the exploited resource, is vital to guarantee the conservation of the resource and the sustainability of the fishery itself. The present study is focused on the Portuguese longline deep-water fishery that targets black scabbardfish. This fish is a deep-water species and its landings have an important economical value for Portugal. The fleet that explores the species is composed by 15 vessels with a mean overall length of 17 m. In the first part of this work Generalized Linear Model was used to standardize the Capture-per-unit-effort, so the first aim is to improve the estimate of CPUE, which is widely used as an index of stock abundance. This is done by reanalyzing the data stored at Portuguese General Directorate from fishery industry and in particularly the logbooks, which are used to record catch data as part of the fisheries regulation. The second part focused on Technical Efficiency, which refers to the ability to minimize the production inputs or the ability to obtain the maximum output. In this study TE estimates were obtained through Stochastic Frontier Analysis. This methodology embraces two science fields, Economy and Statistics, and has been the subject of studies in various areas but there are few applications to fisheries and the available ones are often studied from the economic point of view rather than a statistical one. This work aimed to analyze the quality of the logbooks and identify the relevant factors to the CPUE estimation as the theoretical evaluation of SFA approach and the identification of the statistical differences between several models. TE of each vessel was estimated and was verify if the black scabbardfish fishery operating in Portugal mainland can be considered efficient.