Buyer search and price dispersion:a laboratory study
Posted offer markets with costly buyer search are investigated in 18 laboratory sessions. Each period sellers simultaneously post prices. Then each buyer costlessly observes one or (with probability 1-q) two of the posted prices, and either accepts an observed price, drops out, or pays a cost to search again that period. The sessions vary q, the search cost, and the number and kind of buyers. Equilibrium theory predicts a unified very low (very high) price for q=0 (q=1) and predicts specific distributions of dispersed prices for q=1/3 and 2/3. Actual transaction prices conform rather closely to the predictions, especially in treatments with many robot buyers. Individual buyer and seller behavior, however, differs systematically from the equilibrium predictions: buyers' reservation prices are biased away from the extremes and sellers' posted prices have positive autocorrelation and cross sectional correlation. Learning models can account for a portion of these deviations from equilibrium behavior.