摘要：In this paper, the heterogeneity of crops is recognized and food commodities are disaggregated into varieties of a crop in order to test whether variety attributes influence the size of the marketed surpluses of selling households. The behavior of semi-subsistence banana producing households in Uganda is examined using farm-level survey data collected in 2003. Bananas, the staple crop of the country, are important for meeting immediate consumption requirements and for income generation. The relationship between marketed surpluses and variety attributes is defined theoretically and tested empirically using a semi-parametric censored quantile regression. Inferences are made in two stages to account for differences in the structure of decision-making. Findings suggest that households sell the excess production of varieties that yield larger bunches, while keeping the bunches of varieties with perceived superior quality attributes for own consumption. Reducing transactions costs is perhaps a necessary condition for stimulating market participation, but it is not a sufficient condition for explaining the composition of participation. Provision of information and improvement of market signals related to quality characteristics of specific varieties may also be required in order to stimulate a more disaggregated supply response across varieties. This can, consequently, have implications for crop improvement strategies.
