Simple majority does not reflect the intensity of voters’ preferences. This paper presents an efficient collective choice mechanism when the choice is binary and the designer may use non-trasferable punishments to persuade agents to reveal their private information. The designer faces a dilemma – a punishment may induce a more correct choice, but its cost is socially wasteful. The efficient mechanism is a weighted majority. Weight of each individual is known ex ante and no punishments applied if preferences are relatively homogenous. Eliciting types through punishments in order to construct type-specific weights should occur if preference intensity is relatively heterogeneous, or if voters preferences represent a larger population.
