Health insurance premiums often do not reflect individual health risks, implying redistribution from individuals with low health risks to individuals with high health risks. This paper studies whether more cost-sharing leads to less redistribution and to lower welfare of high-risk individuals....

Online ratings play an important role in many markets. However, how fast they can reveal seller types remains unclear. To study this question, we propose a new model in which a buyer learns about the seller’s type from previous ratings and her own experience and rates the seller if she learns...