The welfare state is not merely a stand-in for missing markets; it can do a whole lot more. When generations overlap and the young must borrow to make educational investments, a dynamically-efficient welfare state, by taxing the middle-aged and offering a compensatory old-age pension, can...

Intergenerational altruism and contemporaneous cooperation are both important to the provision of long-lived public goods. Equilibrium climate protection may depend more sensitively on either of these considerations, depending on the type of policy rule one examines. This conclusion is based on...