3 April 2018It is shown that the presence of informed buyers is necessary but not always sufficient for producers to use prices as signals of product quality. A sufficiently high fraction of informed buyers eliminates the lemons problem. A small fraction of informed buyers mitigates the lemons problem, provided that buyers’ prior belief of high quality is sufficiently pessimistic: price reveals high quality at a signaling cost which increases with market power. However, if buyers’ prior belief of high quality is optimistic when the market is poorly informed, then the lemons problem is not overcome.