As the first, substantive contribution, this paper revisits the effectiveness of two widely used public sponsored training programs, the first one focusing on intensive occupational training and the second one on short-term activation and job entry. We use an exceptionally rich administrative...

This paper provides an empirical investigation of externalities from education in Sweden in an earnings equation framework. The empirical models are estimated on a large sample of matched employees and establishments. External effects of education are identified from the average educational...

We characterize the class of symmetric two-player games in which tit-for-tat cannot be beaten even by very sophisticated opponents in a repeated game. It turns out to be the class of exact potential games. More generally, there is a class of simple imitation rules that includes tit-for-tat but...

We show that in symmetric two-player exact potential games, the simple decision rule imitate-if-better cannot be beaten by any strategy in a repeated game by more than the maximal payoff difference of the one-period game. Our results apply to many interesting games including examples like 2x2...

We show that for many classes of symmetric two-player games, the simple decision rule 'imitate-if-better' can hardly be beaten by any strategy. We provide necessary and sufficient conditions for imitation to be unbeatable in the sense that there is no strategy that can exploit imitation as a...