Consumers and sellers heterogeneity, search costs and spatial price dispersion in retail food markets

— Price dispersion, i.e. a homogeneous product sold at different prices by different sellers, is among the most replicated findings in empirical economics. The paper assesses the extent and determinants of spatial price dispersion for 14 perfectly homogeneous food products in more than 400 retailers in a market characterized by the persistence of a large number of relatively small traditional food stores, side by side with large supermarkets. The extent of observed price dispersion is quite high, suggesting that, despite their large number, monopolistic competition prevails among sellers as a result of the heterogeneity of services offered. When prices in an urban area (where the spatial concentration of sellers is much higher and consumer search costs significantly lower) have been compared with those in smaller towns and rural areas, differences in search costs and the potentially higher degree of competition did not yield lower prices; quite the contrary, they were, on average, higher for 11 of the 14 products considered. Supermarkets proved to be often, but not always, less expensive than traditional retailers, although average savings associated to food shopping at supermarkets were extremely low. Finally, the results of the study suggest that sellers behave differently in their pricing decision strategies; these differences emerge both at the firm level and, for supermarkets, within the same chain. The fact that products considered were homogeneous, purchases frequently repeated, the number of sellers large, and search costs relatively low, did not suffice to keep price dispersion low. Based on the results presented in the paper, it is clear that more important in explaining price dispersion is the contemporaneous heterogeneity of retailers (in terms of services rendered) and consumers (in terms of their propensity to search and shopping preferences), which makes it possible for a monopolistic competition structure of the market to emerge and for small traditional food retail stores to remain in business.