EFICIÊNCIA ECONÔMICA: UMA APLICAÇÃO DO MODELO DE FRONTEIRA ESTOCÁSTICA EM EMPRESAS DE SANEAMENTO

The objective of the present study, is measure the efficiency in the sector of basic sanitation. Verifying the existence of economical efficiency among basic sanitation companies on Sao Paulo State, according to the different products determination, assuming two types of systematical errors (half-normal and truncated-normal), as well as, the covered services: regional and local. To perform that, it has been evaluated the efficiency existence on the companies, on Sao Paulo State, using the data from the 'Sistema Nacional de Informação sobre Saneamento' (SNIS), of 2002, from Cities Ministry; through stochastic frontier models of cost function to each type of output used as the dependent variable. It is possible to conclude that, according to the different determinations of outputs, and the assumed distribution of the systematic error, the results has presented different results. That way, the determination of the efficiency is sensible to the choice of output. Performed tests have showed that covered services of the companies were not significant to determine a result. This allows that is possible decrese costs of this enterprises and hold the service's level.

Brazilian Agricultural Credit Policy Revisited in the Eighties

Several developing countries have used credit policies to achieve agricultural development goals. The Brazilian case is especially revealing because huge amounts of rural credit have been channeled to agriculture, and credit policy was such an important part of agricultural policy during the past couple of decades. This paper reviews Brazilian credit policies and the impact of credit on agriculture over the 1960-1985 period. It serves as an important updating of our earlier paper that analyzed developments as of the mid-1970's [Araujo and Meyer (1978)). This paper includes data from the 1980 census which confirm some of the trends identified in the earlier paper. It also includes new information on the highly controversial issue in Brazil of the magnitude and impact of subsidies provided through negative real interest rates on agricultural loans

Demand for fisheries products in Brazil

Fish consumption per capita in Brazil is relatively modest when compared to other animal proteins. This study analyses the influence of protein prices, other food prices and population income on the fish demand in Brazil. First, the problem of fish supply in Brazil is characterized. It is followed by reviews of the relevant economic theory and methods of Almost Ideal Demand System - AIDS and their elasticity calculations. A descriptive analysis of fish demand in Brazil using the microdata called "Pesquisa de Orçamento Familiar" (Familiar Budget Research) - POF 2002-2003 is presented. Finally, demand functions and their elasticities are calculated for two different cases: one considering five groups of animal proteins (Chicken; Milk and Eggs; Fish; Processed Proteins and Red Meat) and other with seven groups of food categories (Cereals; Vegetables and Fruits; Milky and Eggs; Oils and Condiments; Fish; Other processed foods; and Meats). The main results are: per capita consumption of fish (4.6 kg per inhabitant per year) is low in Brazil because few households consume fish. When only households with fish consumption are considered, the per capita consumption would be higher: 27.2 kg per inhabitant per year. The fish consumption in the North-East Region is concentrated in the low-income class. In the Center-South Region, the fish consumption is lower and concentrated in the intermediate income classes. The main substitutes for fish are the processed proteins and not the traditional types of meat, such as chicken and red meat

Characteristics of sugarcane production in the State of São Paulo, Brazil

Brazil is the largest producer of sugar and ethanol made from sugarcane. It is well known that automobiles in Brazil run on ethanol, but the current conditions of sugarcane production have not yet been explained from the viewpoint of human geography. To present basic data pertaining to sugarcane production, this study reconsiders its characteristics by examining the production elements such as land use, cultivation methods, and the management of cases involving farms, custom harvesters, agricultural cooperatives, machinery manufacturers, and sugar factories. The main data used were obtained from fieldwork conducted in the State of São Paulo. The results show that the vast amounts of land used in Brazil for sugarcane production have developed around the sugarcane production centers, especially those in the State of São Paulo. In this area, the scale of production has grown through the introduction of new technology, mechanization, tenant farming, and single-crop production. The structure of sugarcane production that comprises these elements is complex, but it can be rationalized in terms of economy. With respect to environmental load, there are anxieties about the amount of industrial materials being applied in the course of land use

Concentração do crédito rural no Estado da Bahia no período de 1999 a 2003

O crédito rural é uma das principais políticas de fomento à agricultura, porém os recursos têm sido distribuídos de forma desigual, privilegiando o Sul e o Sudeste brasileiros. O objetivo do presente trabalho foi mensurar a concentração do crédito agrícola na Bahia, dividido em suas mesorregiões, no período de 1999 a 2003. Para tanto, utilizou-se a metodologia do índice T de Theil e da análise tabular dos dados. Os resultados demonstraram concentração do crédito entre as mesorregiões baianas. Apesar de se verificar concentração do crédito pela análise tabular, esta não foi fortemente caracterizada pelo índice T de Theil, que mensurou a distribuição do crédito em relação ao valor da produção. A despeito da elevação do índice no período analisado, verificou-se que esta ainda é baixa em comparação ao seu valor máximo.------------------------------The rural credit is one of the most important agricultural policy finance, however the resources have been distributed in an inequality way, benefiting the brazilian south and southeast regions. This article aims to mensurate the rural credit concentration in the Bahia state, it was divided in its 7 (seven) “mesorregiões”, in the period from 1999 to 2003. Tabular analysis, estimation of Theil T index were used as the basic analytical techniques for the study. The main results of the research show concentration among the “mesorregiões” by tabular analysis, but analyzing by Theil index, this concentration was not perceived. They differ because the Theil index consider the relationship between the credit distribution and agricultural production value. Despite of the elevation in the Theil index in the full period, note that the concentration is lower faced with his higher value.crédito rural, concentração, distribuição, índice T de Theil, Bahia, rural credit, concentration, distribution, Theil index, Agricultural Finance,

Rural credit in Brazil: subsidy, distribution and factors associated with the supply of funds

A presente pesquisa visa alcançar três objetivos básicos. Em primeiro lugar, desenvolve-se uma análise histórica da institucionalização do Sistema Nacional de Crédito Rural, principalmente no que se refere ao volume de recursos alocados e evolução das taxas de juros. Nessa parte do estudo, também se realiza uma análise comparativa entre algumas estatísticas do crédito rural e da evolução do setor agrícola. Em segundo lugar, avaliam-se alguns dos principais problemas e distorções gerados pela política de crédito rural no Brasil, avaliação essa lastreada nos resultados das pesquisas realizadas em período recente relativas ao subsídio implícito nas taxas de juros e à distribuição dos recursos. Finalmente, a pesquisa procura identificar fatores econômicos relevantes que afetam a oferta de crédito rural no Brasil. Para atingir essa meta, ajustam-se modelos econométricos relativos ao período 1969 - 1986. Utilizando-se dados secundários de diversas fontes, é aplicada a técnica de análise tabular para permitir o estudo da evolução dos financiamentos rurais, segundo as atividades, tipos de empréstimo, regiões e agentes financeiros; o mesmo procedimento é aplicado à análise da evolução das taxas de juros. Ênfase é dada à estimativa dos subsídios implícitos nas taxas de juros; além disso, analisa-se o problema distributivo no Brasil e nas suas Grandes Regiões, aplicando-se a entropia e a redundância como medidas de concentração. Na análise dos fatores associados à oferta são ajustadas algumas equações de regressão múltipla nas formas linear e potência. Dentre os principais resultados da pesquisa, destacam-se: a) Houve uma considerável oscilação no volume de créditos concedidos à agricultura no período 1969 - 1986; b) As taxas de juros foram frequentemente alteradas pelas autoridades monetárias, com o propósito de promover ajustamentos de curto prazo; c) As estimativas de subsídio, como calculadas na pesquisa, superam estimativas anteriores que não levaram em conta o tratamento diferenciado dado aos insumos modernos; d) Quando medida pela entropia, a distribuição do crédito rural entre estratos de área não apresenta melhoria significativa no Brasil e na maioria das Grandes Regiões, exceto no caso da Região Sudeste; e) Em contrapartida, a redundância da distribuição do crédito em relação ao valor da produção, no período 1970 - 1980, mostra apreciável redução de concentração entre os estratos de área, exceção feita à Região Nordeste; e, f) O modelo econométrico do tipo potência sugere que os principais fatores associados (positivamente) ao saldo dos empréstimos rurais no Brasil são: Depósitos à Vista nos Bancos Comerciais, Base Monetária e Dívida Pública e Preços Recebidos pelos Agricultores. Essas variáveis explicam grande parte das variações observadas na oferta de recursos financeiros (na forma de saldo devedor).The general purpose of this research is to analyze the agricultural credit policy in Brazil during the 1969 - 1986 period. Special emphasis is given to issues concerning the subsidized interest rate policy, distribution problems at national, regional and farm levels, and to major economic factors associated with the supply of funds for rural credit. Tabular analysis, estimation of entropy and redundancy, and multiple regression models were used as the basic analytical techniques for the study. Census data and Central Bank statistics provided the basic information for the analysis concerning credit issues. Agricultural production and price statistics from IBGE and Getulio Vargas Foundation were also used. The main results of the research are: a) Due to major policy changes, the supply of rural credit exhibited wide variations in the period studied; b) The interest rates for rural loans have changed very frequently as an attempt of Brazilian policymakers to achieve short run adjustments and/or planning policy targets; c) The subsidy rates, as estimated in this research, are considerably higher the previous ones found in the Brazilian literature; d) The distribution of rural loans measured by entropy does not show a significant improvement among different size of farms in the 1970 - 1980 period (with the exception of the Southeast Region); e) When measured by the redundancy, the credit distribution in relation to value of production improved significantly in the same period (with the exception of the Northeast Region); f) The selected econometric models suggest that Demand Deposits at Commercial Banks, Monetary Basis and Public Debt, and Prices Received by Farmers are likely to be positively associated with changes in the volume of rural credit. Also, these variables explain most of the observed changes in the supply of funds

Markov decision processes with imprecise probabilities and relational representations: foundations and algorithms.

Este trabalho é dedicado ao desenvolvimento teórico e algorítmico de processos de decisão markovianos com probabilidades imprecisas e representações relacionais. Na literatura, essa configuração tem sido importante dentro da área de planejamento em inteligência artificial, onde o uso de representações relacionais permite obter descrições compactas, e o emprego de probabilidades imprecisas resulta em formas mais gerais de incerteza. São três as principais contribuições deste trabalho. Primeiro, efetua-se uma discussão sobre os fundamentos de tomada de decisão sequencial com probabilidades imprecisas, em que evidencia-se alguns problemas ainda em aberto. Esses resultados afetam diretamente o (porém não restrito ao) modelo de interesse deste trabalho, os processos de decisão markovianos com probabilidades imprecisas. Segundo, propõe-se três algoritmos para processos de decisão markovianos com probabilidades imprecisas baseadas em programação (otimização) matemática. E terceiro, desenvolvem-se ideias propostas por Trevizan, Cozman e de Barros (2008) no uso de variantes do algoritmo Real-Time Dynamic Programming para resolução de problemas de planejamento probabilístico descritos através de versões estendidas da linguagem de descrição de domínios de planejamento (PPDDL).This work is devoted to the theoretical and algorithmic development of Markov Decision Processes with Imprecise Probabilities and relational representations. In the literature, this configuration is important within artificial intelligence planning, where the use of relational representations allow compact representations and imprecise probabilities result in a more general form of uncertainty. There are three main contributions. First, we present a brief discussion of the foundations of decision making with imprecise probabilities, pointing towards key questions that remain unanswered. These results have direct influence upon the model discussed within this text, that is, Markov Decision Processes with Imprecise Probabilities. Second, we propose three algorithms for Markov Decision Processes with Imprecise Probabilities based on mathematical programming. And third, we develop ideas proposed by Trevizan, Cozman e de Barros (2008) on the use of variants of Real-Time Dynamic Programming to solve problems of probabilistic planning described by an extension of the Probabilistic Planning Domain Definition Language (PPDDL)