The anatomy of prices on the French fish market

Hedonic price regressions have become a standard tool to study how prices of commodity goods are related to quality attributes. In this paper, we extend the traditional price specification by incorporating three sources of unobserved heterogeneity related to sellers, buyers, and matches between buyers and sellers. The extended price specification is estimated on a unique exhaustive dataset of nearly 15 million transactions occurring in French wholesale fish markets from 2002 to 2007. Results show that unobserved heterogeneity plays a significant role in price formation. For some species, its inclusion in price regressions changes the coefficients of quality-related fish characteristics. Last, using data analysis techniques, we classify fish and crustacean species by the extent to which price variations are related to fish characteristics, time effects and the three sources of unobserved heterogeneity.