The Determinants of Consumer Price Dispersion : Evidence from French Supermarkets

We characterize the dispersion of grocery prices in France based on a large original data set of prices in more than 1500 supermarkets. On average across products, the 90th percentile of relative prices is 17 percentage points higher than the 10th and the mean absolute deviation from quarterly average product prices is 5%. We show that temporal price variations (including sales and promotions) explain only little of the observed price dispersion, while the spatial permanent component of price dispersion largely dominates. Price dispersion across stores in France essentially results from persistent heterogeneity in retail chains' pricing, while local conditions regarding demand or competition contribute to a much lower extent