Este estudo investiga os fatores determinantes da eficiência técnica no setor de supermercados brasileiro com base na aplicação de diferentes métodos de fronteira de produção que permitem uma comparação de desempenho entre companhias. Para isso, utilizou-se uma amostra de 85 redes de supermercados em operação no Brasil entre os anos de 2006 e 2015. A metodologia de pesquisa baseou-se em três abordagens de estimação da fronteira de produção: paramétrica, não paramétrica e semiparamétrica. Na primeira, a eficiência é estimada por meio da análise da fronteira estocástica com dados em painel, e diferentes especificações para função de produção. Nessa etapa também são estimados modelos com heterogeneidade a fim de encontrar os determinantes da eficiência dos supermercados. Em seguida os métodos não paramétricos de fronteira são classificados quanto à organização dos dados, primeiramente calculou-se o DEA-Malmquist para dados em painel, e, em seguida a técnica de DEA tradicional para cada ano separadamente. Por fim, os escores de eficiência obtidos pelo DEA são organizados em painel e utilizados como variável dependente na abordagem semiparamétrica, que estima um modelo Tobit para encontrar os determinantes da eficiência. Os resultados de todas as abordagens apontam para a ineficiência do setor de supermercados brasileiro, um alerta às companhias para melhorarem seus processos produtivos. Foi identificada uma queda na eficiência técnica do setor nos últimos anos, enquanto a produtividade apresentou variação positiva, em grande parte causada pela mudança tecnológica. A análise comparativa dos resultados dos modelos mostrou que a escolha da abordagem não influencia no ranking de eficiência, por outro lado a magnitude dos escores de eficiência varia de forma significativa de um método para outro. Os modelos de SFA com heterogeneidade e DEA em dois estágios forneceram resultados diferentes quanto aos determinantes da eficiência, no entanto, na comparação da eficiência média foi possível encontrar evidências do impacto do tamanho, do poder de mercado e da realização de fusões e aquisições sobre a ineficiência dos supermercados, confirmando três das hipóteses propostas na pesquisa. Tais achados representam uma significativa contribuição para literatura sobre eficiência no varejo, ainda pouco explorada no Brasil / This study investigates the determinant technical efficiency factors in the Brazilian supermarket sector based on the application of different production frontier methods that allow a comparison of performance between companies. A sample of 85 supermarket chains operating in Brazil between 2006 and 2015 was used. The research methodology was based on three approaches of estimation of the frontier of production: parametric, non-parametric and semiparametric approach. In the first one, the efficiency is estimated through the analysis of the stochastic frontier with panel data, and different specifications for production function. In this step, models with heterogeneity are also estimated in order to find the determinants of supermarket efficiency. Then the non-parametric frontier methods are classified as to the organization of the data, first the DEA-Malmquist was used for panel data, and then the traditional DEA technique for each year separately. Finally, the efficiency scores obtained by the DEA are organized as a panel and used as the dependent variable in the semiparametric approach, which estimates a Tobit model to find the determinants of efficiency. The results of all approaches point to the inefficiency of the Brazilian supermarket sector, which represents an alert for companies to improve their production processes. In addition, a drop in the sector\'s technical efficiency was identified in recent years, while the productivity showed a positive variation, largely due to technological change. The comparative analysis of the model results showed that the choice of the approach did not influence the construction of the efficiency ranking, on the other hand, the magnitude of the efficiency scores varies significantly between the approaches. SFA models with heterogeneity and two-stage DEA provided different results regarding efficiency determinants; however, in the comparison of the average efficiency it was possible to find evidence of the impact of size, market power and mergers and acquisitions on the supermarket inefficiency, confirming three of the hypotheses proposed in the research. These findings represent a significant contribution to literature on retail efficiency, which is still little explored in Brazil.

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Este estudo investiga os fatores determinantes da eficiência técnica no setor de supermercados brasileiro com base na aplicação de diferentes métodos de fronteira de produção que permitem uma comparação de desempenho entre companhias. Para isso, utilizou-se uma amostra de 85 redes de supermercados em operação no Brasil entre os anos de 2006 e 2015. A metodologia de pesquisa baseou-se em três abordagens de estimação da fronteira de produção: paramétrica, não paramétrica e semiparamétrica. Na primeira, a eficiência é estimada por meio da análise da fronteira estocástica com dados em painel, e diferentes especificações para função de produção. Nessa etapa também são estimados modelos com heterogeneidade a fim de encontrar os determinantes da eficiência dos supermercados. Em seguida os métodos não paramétricos de fronteira são classificados quanto à organização dos dados, primeiramente calculou-se o DEA-Malmquist para dados em painel, e, em seguida a técnica de DEA tradicional para cada ano separadamente. Por fim, os escores de eficiência obtidos pelo DEA são organizados em painel e utilizados como variável dependente na abordagem semiparamétrica, que estima um modelo Tobit para encontrar os determinantes da eficiência. Os resultados de todas as abordagens apontam para a ineficiência do setor de supermercados brasileiro, um alerta às companhias para melhorarem seus processos produtivos. Foi identificada uma queda na eficiência técnica do setor nos últimos anos, enquanto a produtividade apresentou variação positiva, em grande parte causada pela mudança tecnológica. A análise comparativa dos resultados dos modelos mostrou que a escolha da abordagem não influencia no ranking de eficiência, por outro lado a magnitude dos escores de eficiência varia de forma significativa de um método para outro. Os modelos de SFA com heterogeneidade e DEA em dois estágios forneceram resultados diferentes quanto aos determinantes da eficiência, no entanto, na comparação da eficiência média foi possível encontrar evidências do impacto do tamanho, do poder de mercado e da realização de fusões e aquisições sobre a ineficiência dos supermercados, confirmando três das hipóteses propostas na pesquisa. Tais achados representam uma significativa contribuição para literatura sobre eficiência no varejo, ainda pouco explorada no Brasil / This study investigates the determinant technical efficiency factors in the Brazilian supermarket sector based on the application of different production frontier methods that allow a comparison of performance between companies. A sample of 85 supermarket chains operating in Brazil between 2006 and 2015 was used. The research methodology was based on three approaches of estimation of the frontier of production: parametric, non-parametric and semiparametric approach. In the first one, the efficiency is estimated through the analysis of the stochastic frontier with panel data, and different specifications for production function. In this step, models with heterogeneity are also estimated in order to find the determinants of supermarket efficiency. Then the non-parametric frontier methods are classified as to the organization of the data, first the DEA-Malmquist was used for panel data, and then the traditional DEA technique for each year separately. Finally, the efficiency scores obtained by the DEA are organized as a panel and used as the dependent variable in the semiparametric approach, which estimates a Tobit model to find the determinants of efficiency. The results of all approaches point to the inefficiency of the Brazilian supermarket sector, which represents an alert for companies to improve their production processes. In addition, a drop in the sector\'s technical efficiency was identified in recent years, while the productivity showed a positive variation, largely due to technological change. The comparative analysis of the model results showed that the choice of the approach did not influence the construction of the efficiency ranking, on the other hand, the magnitude of the efficiency scores varies significantly between the approaches. SFA models with heterogeneity and two-stage DEA provided different results regarding efficiency determinants; however, in the comparison of the average efficiency it was possible to find evidence of the impact of size, market power and mergers and acquisitions on the supermarket inefficiency, confirming three of the hypotheses proposed in the research. These findings represent a significant contribution to literature on retail efficiency, which is still little explored in Brazil.

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)

Magister Economicae - MEcon / Despite its recent remarkable economic growth, Ethiopia remains one of the poorest countries in the world. More than 80 percent of Ethiopians obtain their livelihood from traditional low-productivity agricultural activities. Due to lack of water storage facilities and the erratic nature of rainfalls, most farmers don’t have access to water to produce more than one crop per year and hence there are frequent crop failures due to droughts which have made the country one of the highest food insecure nations and receiver of food aid. It is evident that a comprehensive effort is required to increase crop and agricultural production through different intensification and productivity enhancement mechanisms and reduce rural household’s food insecurity and poverty. In line with this the Government of Ethiopia and different NGO’s have been promoting irrigation technology as a viable option in enhancing farm productivity and efficiency improvements.By integrating field observations, economic theory, and econometric analysis, this study assess the extent to which access to irrigation technology affects the level of technical efficiency in Gorogutu district of Eastern Ethiopia. The analysis is based on primary household-level data collected from 100 randomly selected households in 20010/11 cropping season. To analyze the effect of the technology on technical efficiency, three different Cobb-Douglas type of Stochastic Production Functions were estimated. More so, to explore different socio- economic and institutional determinants of technical efficiency in the study district, an inefficiency effect model was estimated using the one step procedure.The result from the estimated models has shown that farm households in the study area are not technically efficient and there is a chance to increase output by using the technology and mix of production input used by the best farm household (with 20 percent technical inefficiency). In addition, it also showed that households with access to irrigation technology are more technically efficient (84 percent technical efficiency) than those without access to the technology (77 percent technical efficiency). And household’s access to irrigation technology, access to extension service and distance travelled from farm plot to homestead are a significant determinant of technical efficiency in the study area.The study recommended, among other things, as a country that has a huge potential for irrigation development, utilization of this potential and providing irrigation technology to farm households will have a huge impact on the livelihoods of the majority of the poor. Evidently, efforts tailored towards this end would be very essential in militating against the high levels of poverty that is persistent in the communities

This diploma thesis deals with the stochastic frontier approach -- a tool for the analysis of technical efficiency. First, general outline, basic terms and approaches to efficiency analysis are overviewed. Also the theoretical background of production functions is involved, focused on the Cobb-Douglas production function. Furthermore, the frontier approach and the stochastic frontier approach for cross-sections data is covered. Based on this, stochastic frontier model with time-varying technical efficiency for panel data is introduced with respect to maximum likelihood estimation. The second part offers an application of the model to assess technical efficiency of ice hockey teams in the NHL for the 1997-2013 period. Output of the production is measured by the winning percentage, inputs are salaries of three categories -- goaltender, defenseman and centers/wingers.

Esta dissertaÃÃo busca analisar as diferenÃas tecnolÃgicas da produÃÃo agropecuÃria entre os municÃpios situados nas grandes regiÃes brasileiras, com enfoque especial para o Nordeste brasileiro. Como aporte metodolÃgico, utilizou-se o modelo de meta-fronteira tecnolÃgica proposta por Battese, Rao e OâDonnell (2004) e OâDonnell, Rao e Battese (2008), para responder atà que ponto essas diferenÃas regionais influenciam na eficiÃncia da produÃÃo e qual os seus impactos nos municÃpios. A anÃlise foi dividida em dois modelos. No Modelo 1 propÃs-se analisar e identificar as diferenÃas tecnolÃgicas da produÃÃo agropecuÃria entre os municÃpios situados nas grandes regiÃes brasileiras, exceto pela regiÃo Norte, por questÃes metodolÃgicas. Jà o Modelo 2 voltou-se à diferenciaÃÃo tecnolÃgica da produÃÃo agropecuÃria existente no semiÃrido e no nÃo-semiÃrido do Nordeste. A hipÃtese assumida nesta pesquisa à a existÃncia de um processo de heterogeneizaÃÃo tecnolÃgica do meio rural brasileiro e que esta diferenciaÃÃo impacta no nÃvel de eficiÃncia tÃcnica da produÃÃo agropecuÃria nas diferentes regiÃes do Brasil e mesmo dentro de uma mesma regiÃo. Detectou-se que esta hipÃtese se mostrou verdadeira para os dois Modelos. O Modelo 1 indicou que a tecnologia de produÃÃo agropecuÃria praticadas nos municÃpios situados nas regiÃes Sul e Centro-Oeste sÃo mais avanÃadas. Jà em relaÃÃo ao Modelo 2, os resultados indicaram que, quando comparadas as duas regiÃes, o nÃo-semiÃrido possui a maior eficiÃncia tÃcnica mÃdia em referÃncia à meta-fronteira. / This thesis analyzes the technological differences in agricultural production between municipalities located in the great Brazilian regions, with a special attention on the Brazilian Northeast. As methodological support was utilized the meta-frontier model, proposed by Battese, Rao and OâDonnell (2004) and OâDonnell, Rao and Battese (2008) to answer how these regional differences influence the efficiency of production and like this spatial heterogeneity impacts on municipalitiesâ technical efficiency (TE). The analysis was divided into two models. The first one proposes to analyze and identify the technological differences in agricultural production between the municipalities located in the Brazilian regions, except in the North region, for methodological reasons. On the other hand, the second one searches for the technological differentiation of agricultural production in the semi-arid and non-semiarid regions of the Northeast. For present thesis, the hypothesisis is the existence of a process of technological heterogenization of the Brazilian rural production and that this differentiation affects the level of TE of agricultural production between different regions of Brazil and within the same region as well. It was found that this hypothesis proved to be true for both models. The Model 1 revealed that the production technology practiced in the municipalities located in the South and Center-West regions are more advanced. Regarding the Model 2 indicated that the non-semiarid has the highest average TE with reference to the meta-frontier, when compared to the semiarid region.

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Made available in DSpace on 2014-12-17T14:52:36Z (GMT). No. of bitstreams: 1 KatiaEBC.pdf: 420245 bytes, checksum: ea933f78f725cdad42680643833f131a (MD5) Previous issue date: 2008-12-31 / This Master s Thesis proposes the application of Data Envelopment Analysis DEA to evaluate economies of scale and economies of scope in the performance of service teams involved with installation of data communication circuits, based on the study of a major telecommunication company in Brazil. Data was collected from the company s Operational Performance Division. Initial analysis of a data set, including nineteen installation teams, was performed considering input oriented methods. Subsequently, the need for restrictions on weights is analyzed using the Assurance Region method, checking for the existence of zero-valued weights. The resulting returns to scale are then verified. Further analyses using the Assurance Region Constant (AR-I-C) and Variable (AR-I-V) models verify the existence of variable, rather than constant, returns to scale. Therefore, all of the final comparisons use scores obtained through the AR-I-V model. In sequence, we verify if the system has economies of scope by analyzing the behavior of the scores in terms of individual or multiple outputs. Finally, conventional results, used by the company in study to evaluate team performance, are compared to those generated using the DEA methodology. The results presented here show that DEA is a useful methodology for assessing team performance and that it may contribute to improvements on the quality of the goal setting procedure. / Esta tese de mestrado prop?e utilizar a An?lise de Envolt?ria de Dados - DEA (Data Envelopment Analysis) na avalia??o de economias de escala e economias de escopo no desempenho de equipes de instala??o de circuitos de comunica??o de dados a partir de um estudo em uma empresa de telecomunica??es do Brasil. S?o utilizados dados obtidos junto ? ?rea de Desempenho Operacional da empresa. O resultado da an?lise inicial do conjunto de dados das dezenove equipes de instala??o considera os m?todos orientados a insumos. A partir da? analisa-se a necessidade de restri??es de pesos, pelo m?todo da Regi?o de Garantia, analisando a exist?ncia de pesos com valor igual a zero. Ap?s essa an?lise ? verificado o retorno de escala gerado pelo sistema. Atrav?s de an?lises utilizando os modelos AR-I-C e AR-I-V ? verificada a exist?ncia de retornos vari?veis de escala ao inv?s de retornos constantes, em fun??o disso todos os comparativos finais usam escores obtidos pelo modelo AR-I-V. Em seguida ? verificado se o sistema ? economicamente de escopo pela an?lise do comportamento dos escores em termos de produtos individuais ou m?ltiplos produtos. Por ?ltimo ? feito um comparativo entre os resultados convencionais utilizados pela empresa em quest?o para avaliar o desempenho das equipes e aqueles gerados pela Metodologia DEA. Os resultados apresentados garantem a utilidade da DEA como metodologia para a avalia??o de desempenho dessas equipes podendo contribuir para a melhoria da qualidade do processo de defini??o de metas.

Made available in DSpace on 2014-12-17T14:52:37Z (GMT). No. of bitstreams: 1 SamaryCA.pdf: 539977 bytes, checksum: 04f5275248b46b145b22c75ed28b86b2 (MD5) Previous issue date: 2007-12-31 / This Master s Thesis proposes the application of Data Envelopment Analysis DEA to evaluate the performance of sales teams, based on a study of their coverage areas. Data was collected from the company contracted to distribute the products in the state of Cear?. Analyses of thirteen sales coverage areas were performed considering first the output-oriented constant return to scale method (CCR-O), then this method with assurance region (AR-O-C) and finally the method of variable returns to scale with assurance region (AR-O-V). The method used in the first approach is shown to be inappropriate for this study, since it inconveniently generates zero-valued weights, allowing that an area under evaluation obtain the maximal score by not producing. Using weight restrictions, through the assurance region methods AR-O-C and AR-O-V, decreasing returns to scale are identified, meaning that the improvement in performance is not proportional to the size of the areas being analyzed. Observing data generated by the analysis, a study is carried out, aiming to design improvement goals for the inefficient areas. Complementing this study, GDP data for each area was compared with scores obtained using AR-O-V analysis. The results presented in this work show that DEA is a useful methodology for assessing sales team performance and that it may contribute to improvements on the quality of the management process. / Esta tese de mestrado prop?e utilizar a An?lise de Envolt?ria de Dados - DEA (Data Envelopment Analysis) na avalia??o de desempenho das equipes de vendas a partir de um estudo de suas ?reas de atua??o. S?o utilizados dados obtidos junto ? empresa contratada para distribui??o dos produtos no estado do Cear?. As an?lises das treze ?reas de vendas foram realizadas considerando o m?todo de retorno constante de escala orientado a produto (CCR-O), em seguida, esse m?todo com utiliza??o de regi?o de garantia (AR-O-C) e por ?ltimo o m?todo de retorno vari?vel de escala com utiliza??o de regi?o de garantia (AR-O-V). O m?todo utilizado na primeira abordagem mostra-se inapropriado para este estudo pois apresenta o inconveniente de gerar pesos com valor igual a zero, permitindo que uma ?rea avaliada obtenha escore m?ximo n?o produzindo. Utilizando-se restri??es de pesos, atrav?s dos m?todos da Regi?o de Garantia AR-O-C e AR-O-V, identificam-se a exist?ncia de retornos decrescentes de escala significando que a melhoria de desempenho n?o ? proporcional ao tamanho das ?reas analisadas. Atrav?s do m?todo AR-O-V foram encontradas nove ?reas eficientes. Observando os dados gerados pelas an?lises faz -se um estudo para projetar metas de melhoria para as ?reas ineficientes. Complementando o estudo, comparam-se os dados do PIB de cada ?rea com os escores obtidos na an?lise A R-O-V. Os resultados apresentados nesse trabalho garantem a utilidade da DEA como metodologia para a avalia??o de desempenho das equipes de vendas podendo contribuir para a melhoria da qualidade do seu processo de gest?o.