摘要：the present study aims to analyze the behavioral assumptions of agents of the dairy chain and to identify the influences that such behaviors have on transaction costs, taking into account the relationship between the Mixed Farming Cooperative of Bela Vista de Goiás (Cooperbelgo) and its members. Attributes of transactions and market governance structure present in the dairy production chain are also described, taking into consideration the study region that is the municipality of Bela Vista de Goiás, Goiás state, Brazil, based in the principles of the New Institutional Economics (NIE). The study was done through exploratory and descriptive research, based on the case study, using documents, and literature review. It was mainly observed that behavioral assumptions and transaction attributes do not increase the amount of transaction costs in the dairy chain since the relations between cooperative and its members are characterized by high frequency, reliability, loyalty, and scarce presence of opportunistic behaviors and uncertainties. As a case study, results may not be simply extrapolated to other different realities. As a case study, results may not be simply extrapolated to other different realities but are useful to exemplify how the behavioral assumptions and the attributes of transactions may influence the magnitude of transaction cost in a real agri-food chain. Cooperative arrangements create trust among agents, reducing the risk for transaction cost promoting behaviors such as opportunism. Provides information about one of the most growing dairy regions in Brazil.
关键词：Dairy production chain;Behavioral assumptions;Transaction attributes.
