Private politics are often introduced by market participants in the absence of public regulation. But when is private politics enough, efficient, or better than administratively costly public regulation? We present a novel framework in which we can study the interaction between regulation,...

In public good games, voluntary contributions tend to start of high and decline as the game is repeated. If high contributors are matched, however, contributions tend to stay high. We propose a formalization predicting that high contributors will selfselect into groups committed to charitable...

People benefit from being perceived as trustworthy. Examples include sellers trying to attract buyers, or candidates in elections trying to attract voters. In a laboratory experiment using exchange games, in which the trustor can choose the trustee, we study whether trustees can signal their...