This paper considers an economy where individuals differ in productivity and in risk. Rochet (1991) has shown that when private insurance markets offer full coverage at fair rates, social insurance is desirable if and only if risk and productivity are negatively correlated. This condition is...

This paper studies the design of health insurance with ex post moral hazard, when there is imperfect competition in the market for the medical product. Various scenarios, such as monopoly pricing, price negotiation or horizontal differentiation are considered. The insurance contract specifies...