The structure of two-valued coalitional strategy-proof social choice functions

Abstract

The paper investigates the structure of coalitional strategy-proof social choice functions – CSP scfs, for short – whose range is a subset of cardinality two of an arbitrary set A of alternatives. The study is conducted in the case where the voters/agents are allowed to express indifference among elements of A, and the domain of the scfs consists of preference profiles P=(Pv)v∈V over a society V of arbitrary cardinality. A representation formula for the two-valued CSP scfs is obtained that provides the structure of such functions.