O objetivo foi estudar a política de centrais de abastecimento-filosofia, conceitos e objetivos-utilizando-se como estudo de caso a Ceasa de piracicaba-sp. Consideraram-se aspectos funcional e estrutural e o grau de desigualdade e de concentração de vendedores, a elasticidade de transmissão de preços e as margens de comercialização de alface, abobrinha, cebola, repolho, tomate e laranja, no período de marco de 1985/89. Os resultados dos índices de gini, de concentração econômica e de herfindahl indicaram alto grau de desigualdade e de concentração de vendedores. As elasticidades indicaram que uma variação de preços na Ceasa provoca variação menos que proporcional no varejo. As margens do varejão para abobrinha, repolho, tomate e laranja indicam que e seguida política mista de markup e componente fixo. E indireta a relação de preços entre Ceasa e feira, para cebola e laranja, com política mista de markup e componente fixo para todos produtos. Não houve incentivo para centralização do atacado na Ceasa, com continuidade de pontos tradicionais de comercialização no centro da cidade,decréscimo no numero de agentes em relação ao antigo entreposto e no volume comercializado por agente e com queda de participação da Ceasa no volume total comercializado pelas centrais de abastecimento do estado de Sao Paulo

The main objective of this study was to analyse the wholesale markets for agricultural products represented by the Centrais de Abastecimento - CEASAs (Wholesale Centers for Agricultural Products). In order to attain that objective, the main characteristics of the inicial project proposal (phylosophy, concepts and objectives) were described and compared to the present situation using local CEASA as a study case. The functional as well as the structural aspects of marketing were taken into account in the analysis. Also, sellers concentration and inequality, elasticity of price transmission and gross margin at the wholesale level were calculated for: lettuce, Summer squash, onion, cabbage, tomato and orange, for the period March 1985 to March 1989. Sellers inequality and concentration were estimated by Gini, Herfindahl and Economic Concentration indices. The results for Gini indices showed a high inequality for the following products: lettuce, 0.95; Summer squash, 0.97; onion, 0.94; cabbage, 0.96; tomato, 0.96; and orange, 0.94. The Economic Concentration indices for the eight largest sellers are the following: lettuce, 0.95; Summer squash, 0.74; onion, 0.96; cabbage, 0.72; tomato, 0.89 and orange, 0.95. The Herfindahl indices are: lettucce, 0.15; Summer squash, 0. 22; onion, 0.48; cabbage, 0.17; tomato, 0.30; and orange 0.49. The elasticity of price transmission from CEASA to varejões (a special kind of retailer) were: lettuce, 0.92; Summer squash, 0.67; onion, 0.87; cabbage, 0.57; tomato, 0.83 and orange, 0.21. The elasticity of price transmission, from CEASA to feiras were: lettuce, 0.81; Summer squash, 0.64; onion, 0.78; cabbage, 0.76; tomato, 0.82 and orange, 0.23. The estimated elasticity of price transmission are all lower than 1 which means that for a given change prices at CEASA, there is a less than proportional price variation at the retail level. The results also showed margin at the retail level (varejão and feira) had a component related to CEASA and another independent component, that is, markup and a fixed component policy. Finally, there are evidences indicating that the initial objective of concentrating wholesalers at Piracicaba's CEASA was not successful. The most important evidences are: a) traditional wholesale marketing places continue to exist in the central part of the city; b) the number of wholesalers decreased 8.9%; c) the marketed volume per wholesaler decreased 53.8%; and, finally; d) there was a significant reduction in the size (marketed volume) of local CEASA with respect to total marketed volume by the Centrais de Abastecimento in the State of São Paulo.