We show that for many classes of symmetric two-player games, the simple decision rule \imitate-the-best" can hardly be beaten by any other decision rule. Weprovide necessary and sufficient conditions for imitation to be unbeatable and showthat it can only be beaten by much in games that are of...

Sick-pay is a common provision in labor contracts. It insures workersagainst a sudden loss of income due to unexpected absences andhelps them smooth consumption. Therefore, many governments findsick-pay socially desirable and choose to mandate its provision. Butsick-pay is not without its...