Open AccessSequential voting and agenda manipulation
Author(s) -
Barberà Salvador,
Gerber Anke
Publication year - 2017
Publication title -
theoretical economics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 4.404
H-Index - 32
eISSN - 1555-7561
pISSN - 1933-6837
DOI - 10.3982/te2118
Subject(s) - voting , simple (philosophy) , preference , scope (computer science) , mathematical economics , cardinal voting systems , domain (mathematical analysis) , computer science , majority rule , microeconomics , economics , law and economics , political science , mathematics , artificial intelligence , law , politics , mathematical analysis , philosophy , programming language , epistemology
We study the possibilities for agenda manipulation under strategic voting for two prominent sequential voting procedures: the amendment procedure and the successive procedure. We show that a well known result for tournaments, namely that the successive procedure is (weakly) more manipulable than the amendment procedure at any given preference profile, extends to arbitrary majority quotas. Moreover, our characterizations of the attainable outcomes for arbitrary quotas allow us to compare the possibilities for manipulation across different quotas. It turns out that the simple majority quota maximizes the domain of preference profiles for which neither procedure is manipulable, but at the same time neither the simple majority quota nor any other quota uniformly minimizes the scope of manipulation once this becomes possible. Hence, quite surprisingly, simple majority voting is not necessarily the optimal choice of a society that is concerned about agenda manipulation.