Power index research has been a very active field in the last decades. Will this continue or are all the important questions solved? We argue that there are still many opportunities to conduct useful research with and on power indices. Positive and normative questions keep calling for...

Health shocks are among the most important unprotected risks for microfinance clients, but the take-up of micro health insurance typically remains limited. This paper attributes low enrolment rates to a social dilemma. Our theory is that in jointly liable groups, insurance is a public good....

Transparent decision-making processes are widely regarded as a prerequisite for the working of a representative democracy. It facilitates accountability, and citizens may suspect that decisions, if taken behind closed doors, do not promote their interests. Why else the secrecy? We provide a...

A ranking method assigns to every weighted directed graph a (weak) orderingof the nodes. In this paper we axiomatize the ranking method that ranksthe nodes according to their outflow using four independent axioms. This outflowranking method generalizes the ranking by outdegree for directed...

In experimental investigations of the effect of real incentives, accountability—the implicit or explicit expectation of a decision maker that she may have to justify her decisions in front of somebody else—is often confounded with the incentives themselves. This confounding of accountability...

This discussion paper led to a chapter in .Voting Power and Procedures: Essays in Honour of Dan Felsenthal and Moshé Machover', (eds. R. Fara, D. Leech, and M. Salles), pp 41-64, 2014. The main purpose of the present paper is to disentangle the mix-up of the notions of success and satisfaction...

We introduce the prediction value (PV) as a measure of players’ informational importance in probabilistic TU games. The latter combine a standard TU game and a probability distribution over the set of coalitions. Player i’s prediction value equals the difference between the conditional...

There are many situations in which different groups make collective decisions by committee voting, with each group represented by a single person. A natural question is what voting system such a committee should use. Concepts based on voting power provide guidelines for this choice. The two most...

We develop a theoretical framework for studying the effects of interaction on the quaJity of decision-making by monetary policy committees. We show that interaction, i.e. increasing one's expertise through an exchange of views, is most likely not to result in interdependent voting...

There are many situations in which different groups make collective decisions by committee voting, where each group is represented by a single person. Theoretical concepts suggest how the voting systems in such committees should be designed, but these abstract rules can usually not be...