We measure the revenue and cost implications to supermarkets of changing their price positioning strategy in oligopolistic downstream retail markets. Our estimates have implications for long-run market structure in the supermarket industry, and for measuring the sources of price rigidity in the economy. We exploit a unique dataset containing the price-format decisions of all supermarkets in the U.S. The data contain the format-change decisions of supermarkets in response to a large shock to their local market positions: the entry of Wal-Mart. We exploit the responses of retailers to WalMart entry to infer the cost of changing pricing-formats using a .revealed-preference. argument similar to the spirit of Bresnahan and Reiss (1991). The interaction between retailers and Wal-Mart in each market is modeled as a dynamic game. We find evidence that suggests the entry patterns of WalMart had a significant impact on the costs and incidence of switching pricing strategy. Our results add to the marketing literature on the organization of retail markets, and to a new literature that discusses implications of marketing pricing decisions for macroeconomic studies of price rigidity. More generally, our approach which incorporates long-run dynamic consequences, strategic interaction, and sunk investment costs, outlines how the paradigm of dynamic games may be used to model empirically firms' positioning decisions in Marketing.
