A Local-Dominance Theory of Voting Equilibria

It is well known that no reasonable voting rule is strategyproof. Moreover, the common Plurality rule is particularly prone to strategic behavior of the voters and empirical studies show that people often vote strategically in practice. Multiple game-theoretic models have been proposed to better understand and predict such behavior and the outcomes it induces. However, these models often make unrealistic assumptions regarding voters' behavior and the information on which they base their vote. We suggest a new model for strategic voting that takes into account voters' bounded rationality, as well as their limited access to reliable information. We introduce a simple behavioral heuristic based on \emph{local dominance}, where each voter considers a set of possible world states without assigning probabilities to them. This set is constructed based on prospective candidates' scores (e.g., available from an inaccurate poll). In a \emph{voting equilibrium}, all voters vote for candidates not dominated within the set of possible states. We prove that these voting equilibria exist in the Plurality rule for a broad class of local dominance relations (that is, different ways to decide which states are possible). Furthermore, we show that in an iterative setting where voters may repeatedly change their vote, local dominance-based dynamics quickly converge to an equilibrium if voters start from the truthful state. Weaker convergence guarantees in more general settings are also provided. Using extensive simulations of strategic voting on generated and real preference profiles, we show that convergence is fast and robust, that emerging equilibria are consistent across various starting conditions, and that they replicate widely known patterns of human voting behavior such as Duverger's law. Further, strategic voting generally improves the quality of the winner compared to truthful voting

Electoral System Failure in the 2017 French Elections

Abstrac

Democracy, Dictatorship and Economic Performance in Chile

TBPolitical Systems, Economic growth

The Most Dangerous Justice: Measuring Judicial Power in the Lamer Court, 1991-97

The Suoreme Court is an important national institution, but it is also nine individuals with differing conceptions of the law, the constitution and the judicial role. When the Court divides, which it does about half the time, some judges tend more often than others to write or to sign the reasons that constitute the decision of the Court. This article explores the notion of judiciapl ower by looking at the way that judges have written opinions and signed on to the opinions of others for the first seven years of this decade, looking for the most powerful (melodramatically: the most dangerous ) justice. It concludes by speculating about the implications of Justice La Forest\u27s retirement and Justice Sopinka\u27s death

Laboratory Experiments in Political Economy

Most of the laboratory research in political science follows the style that was pioneered in experimental economics a half-century ago by Vernon Smith. The connection between this style of political science experimentation and economics experimentation parallels the connection between economic theory and formal political theory.