In this paper we study learning procedures when counterfactuals (payo s of not-chosen actions) are not observed. The decision maker reasons in two steps: First, she updates her propensities for each action after every payo experience, where propensity is de ned as how much she prefers each...

We study a setting where players are matched into pairs to play a Prisoners' Dilemma game. In the model presented, players are not rational; they simply imitate the more successful actions they observe. Furthermore, a certain correlation is added to the matching process: players that belong to a...

We analyse committees of voters who take a decision between two options as a two- stage process. In a discussion stage, voters share non-verifiable information about a private signal concerning what is the best option. In a voting stage, votes are cast and one of the options is implemented. We...

The costs associated with unhealthy food consumption are not only paid by those suffering from overweight but by all members of society in terms of higher costs for social security systems. With this in mind, we study the effectiveness of a tax, a subsidy and cash incentives in reducing...