Public debt can be optimal in standard incomplete market models with infinitely lived agents, since the associated capital crowd-out induces a higher interest rate. The higher interest rate encourages individuals to save and, hence, better self-insure against idiosyncratic labor earnings risk....

A well‐established result in the literature is that Social Security reduces steady state welfare in a standard life cycle model. However, less is known about the historical quantitative effects of the program on agents who were alive when the program was adopted. In a computational life cycle...