Strategy-proof consensus rules for committee elections

The committee election problem is to choose from a finite set S of candidates a nonempty subset of committee members as the consequence of an election in which each voter expresses a preference for a candidate in S. We use ideas of vote concentration to formulate families of committee election rules, which may exhibit several natural, intuitively appealing properties. One concept of vote concentration, a typification of committee strength, ensures that the associated committee election rule is strategy-proof and so is not subject to voter manipulation.