Individual Powers and Social Consent: An Axiomatic Approach

We introduce a notion of conditionally decisive powers of which the exercise depends on social consent. Decisive powers, or the so-called libertarian rights, are examples and much weaker forms of powers are covered by our notion. We provide an axiomatic characterization of existence of a system of powers and its uniqueness as well as characterizations of various families of rules represented by systems of powers. Critical axioms are monotonicity, independence, and symmetric linkage (person i and i's issues should be treated symmetrically to person j and j's issues for at least one linkage between issues and persons).