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...

A fat and a healthy good provide immediate gratification, and cause health costs or benefits in the long run, which are misperceived. Additionally, the fat good (healthy good) increases (decreases) health care costs by increasing (decreasing) the probability of suffering from a chronic disease...