In repeated normal-form (simultaneous-move) games, simple penal codes (Abreu, 1986, 1988) permit an elegant characterization of the set of subgame-perfect outcomes. We show that the logic of simple penal codes fails in repeated extensive-form games. By means of examples, we identify two types of...

In the real world, public pay-as-you-go pension (PAYG) schemes are popular and co-exist with private, retirement-saving schemes. This is true even in dynamically efficient economies where such pensions offer a lower return. The classic Aaron-Samuelson result argues that, in theory, this is...