Referenda and Partial Commitment in Policy Making *

We study quasi-referenda: two-stage decision processes in which a large number of privately informed agents each answer a binary question, and their collective response constrains the policy options from which a principal must then choose. Across all quasi-referenda, our analysis singles out procedures in which the collective acts as a gatekeeper that authorizes or blocks an extreme policy while otherwise delegating choice to the principal. These procedures maximize the principal's payoff guarantee (the worst-case payoff across all equilibria and information structures) within the class of all quasi-referenda, and when the policy space is fine, they robustly yield near-full-information outcomes. Our results provide a rationale for referenda used in practice and, more broadly, highlight commitment as an important dimension of political institutions.