"We present a simple model in which rational but uninformed traders occasionally chase noise as if it were information, thereby amplifying sentiment shocks and moving prices away from fundamental values. We fill a theoretical gap in the literature by showing conditions under which noise traders...

"Analyses of public policy regularly express certitude about the consequences of alternative policy choices. Yet policy predictions often are fragile, with conclusions resting on critical unsupported assumptions. Then the certitude of policy analysis is not credible. This paper develops a...

"Affirmative action policies are practiced around the world. This paper explores the welfare economics of such policies. A model is proposed where heterogeneous agents, distinguished by skill level and social identity, compete for positions in a hierarchy. The problem of designing an efficient...

"The NBER Bulletin on Aging and Health provides summaries of publications like this. You can sign up to receive the NBER Bulletin on Aging and Health by email. A positive correlation between insurance coverage and ex post risk can be an indicator for private information in insurance markets....