This paper studies the design of a nonlinear social security scheme in a society where individuals differ in two respects: productivity and degree of myopia. Myopic individuals may not save enoughʺ for their retirement because their myopic selfʺ emerges when labor supply and savings decisions...

This paper studies a problem of non linear taxation when individuals have different longevities resulting from a non-monetary effort (like exercising). We first present the laissez-faire and the first best. Like Becker and Philipson (1998), we find that the laissez-faire level of effort is too...