We introduce a class of two-player cooperation games where each player faces a binary decision, enter or exit. These games have a unique Nash equilibrium of entry. However, entry imposes a large enough negative externality on the other player such that the unique social optimum involves the...

We experimentally test for the effect of an additional alternative on the measured risk preferences of farmers in rural Peru. In our experiment, subjects revealed their risk preferences with a series of choices between two gambles. We added a third gamble, which was always dominated by one of...