Discussion paper

DP14183 Abortions, Brexit and Trees

We study how parliaments and other committees vote to select one out of several alternatives in situations where not all available options
can be ordered along a \left-right" axis. Practically all democratic parliaments routinely use Sequential Binary Voting Procedures in or-
der to select one of several alternatives. Which agendas are used in practice, and how should they be designed ? We assume that pref-
erences are single-peaked on an arbitrary tree and we study convex agendas where, at each stage in the sequential, binary voting process,
the tree of remaining alternatives is divided in two subtrees that are subjected to a binary Yes-No vote. In this wide class of situations we
show that dynamic, strategic voting is congruent with sincere, unsophisticated voting even if agents are privately informed, and no matter
what their beliefs about other voters are. We conclude the paper by illustrating the empirical implications of our results for two large case
studies from Germany and from the UK.


Moldovanu, B and (2019), ‘DP14183 Abortions, Brexit and Trees‘, CEPR Discussion Paper No. 14183. CEPR Press, Paris & London. https://cepr.org/publications/dp14183