In this paper we combine a non-cooperative decision-making game in a federal structure with two levels of interest and an incomplete contract which sets the rules of the game. The question we pose is how to combine ex ante efficiency of the design with ex post efficiency of the outcomes in the...

The decision-making rules of the European Union (EU) are defined in an incomplete contract signed by 15 national governments. The design of the contract defines the set of policy issues where it applies – in decision-making rules i.e. the majority rules and the division of powers among the...

A team must select among competing projects that differ in their payoff consequences for its members. Each agent chooses a project and exerts costly effort affecting its random completion time. When one or more projects are complete, agents bargain over which one to implement. A consensus...

We analyze costly information acquisition and information revelation in groups in a dynamic setting. Even when group members have perfectly aligned interests the group may inefficiently delay decisions. When deadlines are far away, uninformed group members freeride on each others' efforts to...

I develop a model of group decision-making, in which a committee generates proposals and holds open discussions, but the ultimate decision is either taken by a leader (decision by authority) or by majority vote. Optimal communication processes are studied that combine both cheap talk statements...

Group liability is often portrayed as the key innovation that led to the explosion of the microcredit movement, which started with the Grameen Bank in the 1970s and continues on today with hundreds of institutions around the world. Group lending claims to improve repayment rates and lower...

In a Hotelling duopoly model, we introduce quality that is more appreciated by closer consumers. Then higher common quality raises equilibrium prices, in contrast to the standard neutrality result. Furthermore, we allow consumers to buy one out of two goods (single-purchase) or both...