We study optimal nonlinear income taxation when earnings can differ because of both ability and luck, so the income tax has both a redistributive role and an insurance role. A substantial literature on optimal redistribution in the absence of uncertainty has evolved since Mirrlees' original...

Government spending on the elderly is projected to increase rapidly as the American population becomes older. As a result, many policymakers and budget analysts are concerned about the continued viability of entitlement programs such as Social Security. The Social Security trustees' economic...