People exhibit group reciprocity when they retaliate, not against the person who harmed them, but against somebody else in that person's group. Group reciprocity may be a key motivation behind intergroup conflict. We investigated group reciprocity in a laboratory experiment. After a group...

Voters in democracies can learn from the experience of neighbouring states: about policy in a direct democracy (`policy experimentation'), about the quality of their politicians in a representative democracy (`yardstick competition'). Learning between states creates spillovers from policy...

Surprisingly high levels of within-group cooperation are observed in conflict situations. Experiments confirm that external threats lead to higher cooperation. The psychological literature suggests proximate explanations in the form of group processes, but does not explain how these processes...

We examine why heterogenous communities may fail to provide public goods. Current work characterizes sanctioning free-riders as an under-supplied public good. We argue that often free-riders can be punished by the coordinated action of a group. This punishment can be profitable, and need not be...

Field studies of conflict report cycles of mutual revenge between groups, often linked to perceptions of intergroup injustice. We test the hypothesis that people are predisposed to reciprocate against groups. In a computerized laboratory experiment, subjects who were harmed by a partner’s...

In the tight budgetary conditions following the 2008 financial crisis, governments have proposed saving money by reforming public services. This paper argues that tight budget constraints make reform harder by introducing an information problem. Governments are uncertain about bureaucratic...

We report an experiment on the Probabilistic Serial (PS) mechanism for allocating indivisible goods. The PS mechanism, a recently discovered alternative to the widely used Random Serial Dictatorship mechanism, has attractive fairness and efficiency properties if people report their preferences...

We report an experiment on the Probabilistic Serial (PS) mechanism for allocating indivisible goods. The PS mechanism, a recently discovered alternative to the widely used Random Serial Dictatorship mechanism, has attractive fairness and efficiency properties if people report their preferences...

All rulers face political competition, both from rivals within their state, and from other states to which their subjects may exit. In a simple model, both kinds of competition are substitutes. Internal competition (democracy) bene?ts citizens by allowing them to replace rent-seeking rulers. But...

In existing models of direct democratic institutions, the median voter beneï¬ts, but representative politicians are harmed since their policy choices can be overridden. This is a puzzle, since representative politicians were instrumental in creating these institutions. I build a model of...