I study reputation models in which information about the long-run player's past behavior is dispersed among short …-run players. I identify two challenges to reputation building when such information is aggregated via the short-run players …-run player's current period action, I propose a resistent to learning condition under which reputation fails. This is because the …

monopolistic certifier can be hump-shaped in its reputation for accuracy: a higher accuracy attracts high-quality sellers but … one certifier, competition plays a disciplining role and the region where reputation is bad shrinks. Conversely, this …