Voting Agendas and Preferences on Trees: Theory and Practice

We study how parliaments and committees select one out of several alternatives when options cannot be ordered along a “left-right” axis. Which voting agendas are used in practice, and how should they be designed? We assume preferences are single-peaked on a tree and study convex agendas where, at each stage in the voting process, the tree of remaining alternatives is divided into two subtrees that are subjected to a Yes-No vote. We show that strategic voting coincides with sincere, unsophisticated voting. Based on inference results and revealed preference arguments, we illustrate the empirical implications for two case studies.