Voting by Veto
Political Science
Final Report Abstract
"Voting by Veto" developed by Dennis C. Mueller is a voting mechanism for decision making among small and medium-sized groups. In brief, Voting by Veto works as follows: In an n-member group, a Voting by Veto decision consists of two stages. In the first stage, every member of the committee makes a proposal. The proposals are joined with the current status quo (or another fallback option), so that there are n+1 alternatives to choose from. For the second stage, a random mechanism determines the order of voting and the committee members sequentially eliminate one alternative each. After every committee member has exercised her veto, a single winning alternative remains. Voting by Veto has never been used in any real-world group decision. Hence, the actual workings of the decision rule are still largely unknown. From a theoretical perspective, Voting by Veto inheres both majoritarian as well as egalitarian tendencies. On the one hand, the voting rule has theoretical fairness properties that are highly desirable in contexts where groups face intense conflicts. Thus, Voting by Veto might offer an innovative institutional resolution for moderating conflicts by fostering consensual decision making. On the other hand, the fairness properties of Voting by Veto can be foiled by collusive behavior of subjects. Theoretically, the mechanism is prone to falling prey to the tyranny of the majority if some group members form coalitions in order to exploit other members of their group. When institutions such as Voting by Veto do not exist in the observational world, laboratory experiments are an ideal method for generating empirical evidence. In several series of experiments with more than 900 participants, the project investigates the influences of group size, communication, social preferences and different conceptions of social justice on group choices under Voting by Veto. Most of the experimental findings indicate that Voting by Veto does indeed promote consensual decision making and might thus provide a suitable decision rule for groups facing intense conflict. However, the project also identifies certain qualifications to this finding. For instance, when communication among group members is private, Voting by Veto is liable to falling prey to the tyranny of the majority. In order to learn something about the potential real-world applicability of Voting by Veto, all participants of the laboratory experiments answered a questionnaire about their opinions on the voting rule. 89% of all participants stated that Voting by Veto is not too complicated and its mechanics can be easily learned. According to 55% of the respondents, Voting by Veto leads to fair decisions and 65% were satisfied with the outcomes of group decisions. Only 33% of all participants believed in the real-world applicability of the voting rule. This expressed skepticism is evidence for the necessity of further research on the workings of Voting by Veto in more realistic settings such as lab-in-the-field experiments or field experiments.
Publications
- 2019. The influence of group size on distributional fairness under voting by veto. European Journal of Political Economy 56: 90-102
Sauermann, Jan, and Paul Beckmann
(See online at https://doi.org/10.1016/j.ejpoleco.2018.07.008)
