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...

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...

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...

Power is a core concept in the analysis and design of organizations. One of the problems with the extant literature on positional power in hierarchies is that it is mainly restricted to the analysis of power in terms of the bare positions of the actors. While such an analysis informs us about...

Collective decision procedures should balance the incentives they provide toacquire information and their capacity to aggregate private information. In a decisionproblem in which a project can be accepted or rejected once information about its qualityhas been acquired or not, we compare the...

In a system of proportional representation, we study the interaction between a voter's turnout decision and her party choice, and how these relate to party polarization. Quantal response equilibria predict such interaction effects. In particular they predict (i) a Polarization Effect: reduced...

We theoretically and experimentally study voter behavior in a setting characterized by plurality rule and mandatory voting, where voters choose from three options. We are interested in the occurrence of strategic voting in an environment where Condorcet cycles may occur. In particular, we focus...

We study the issue of assigning weights to players that identify winning coalitions in plurality voting democracies. For this, we consider plurality games which are simple games in partition function form such that in every partition there is at least one winning coalition. Such a game is said...

Interest groups are introduced in a spatial model of electoral competition between two political parties. We show that, by coordinating voting behavior,these interest groups increase the winning set, which is defined as the set of policy platforms for the challenger that will defeat the...

Interest groups are introduced in a spatial model of electoral competition between two political parties. We show that the presence of these interest groups increases the winning set, which is the set of policy platforms for the challenger that will defeat the incumbent. Therefore interest...