Influence of Informed Buyers in Markets Susceptible to the Lemons Problem
证明知情买家的存在是生产者用价格传递质量信号的必要但不充分条件；当知情买家比例足够高时能消除柠檬问题，比例较低时则取决于买家对高质量的先验信念是否足够悲观。
It 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.