We use a competitive search (price-posting) framework to experimentally examine how buyer information and fairness perceptions affect market behavior. We observe that moving from 0 to 1 uninformed buyers leads to higher prices in both 2(seller)x2(buyer) and 2x3 markets: the former as predicted under standard preferences, the latter the opposite of the theoretical prediction. Perceptions of fair priceselicited in the experiment-are a powerful driver of behavior. For buyers, fair prices correlate with priceresponsiveness, which varies systematically across treatments and impacts sellers' pricing incentives. For sellers, fair prices correlate with underpricing , which also varies systematically across treatments.