Number of sellers, average prices, and price dispersion

A variety of models provide differing predictions regarding the effect of an increase in the number of competitors in a market (seller density) on prices and price dispersion. We review different approaches to generating equilibrium price dispersion and then empirically estimate the relationship between seller density, average product price and price dispersion in the retail gasoline industry using four unique gasoline price data sets. Controlling for station-level characteristics, we find that an increase in station density consistently decreases both price levels and price dispersion across four geographical areas. (C) 2004 Elsevier B.V. All rights reserved.