In analyses of strategy-proof voting, two results feature prominently: the dictatorial characterization contained in the Gibbard-Satterthwaite theorem and the voting by committees characterization in the Barbera-Sonnenschein-Zhou theorem. The two theorems are based on voting procedures defined on the domain of strict preferences. In the present study, we derive corresponding results for voting schemes defined on the full domain of weak preferences and obtain a characterization by means of a combination of sequential dictatorship and voting by extended committees.
Subject classification (UKÄ)
- Barbers-Sonnenschein-Zhou theorem
- strategy-proof voting
- Gibbard-Satterthwaite theorem