Sincere versus sophisticated voting when legislators vote sequentially

Elsewhere (Groseclose and Milyo 2010), we examine a game where each legislator has preferences over (i) the resulting policy and (ii) how he or she votes. The latter preferences are especially important when the legislator is not pivotal. We show that when the game follows the normal rules of legislatures—most important, that legislators can change their vote after seeing how their fellow legislators have voted—then the only possible equilibrium is one where all legislators ignore their policy preferences. That is, each legislator votes as if he or she is not pivotal. The result, consistent with empirical studies of Congress, suggests that legislators should tend to vote sincerely, rather than sophisticatedly. In this paper we examine how outcomes change if we change the rules for voting. Namely, instead of a simultaneous game, we consider a game where legislators vote sequentially in a pre-determined order. We show that, opposite to the simultaneous game, an alternative wins if and only if a majority of legislators’ policy preferences favor that alternative. Our results suggest that if Congress adopted this change in rules, then sophisticated voting would become frequent instead of rare.     

Policy convergence in a two-candidate probabilistic voting model

We propose a generalization of the probabilistic voting model in two-candidate elections. We allow the candidates have general von Neumann–Morgenstern utility functions defined over the voting outcomes. We show that the candidates will choose identical policy positions only if the electoral competition game is constant-sum, such as when both candidates are probability-of-win maximizers or vote share maximizers, or for a small set of functions that for each voter define the probability of voting for each candidate, given candidate policy positions. At the same time, a pure-strategy local Nash equilibrium (in which the candidates do not necessarily choose identical positions) exists for a large set of such functions. Hence, if the candidate payoffs are unrestricted, the “mean voter theorem” for probabilistic voting models is shown to hold only for a small set of probability of vote functions.     

Jury theorems with multiple alternatives

I consider a game in which imperfectly informed jurors vote to select one of several possible choices when there is a natural ordering of the possibilities. Each juror votes for the largest alternative the juror would like to implement, and the alternative that is selected is the largest alternative supported by a given number of jurors. For non-unanimous voting rules, the probability of a mistaken judgment goes to zero as the number of jurors goes to infinity. I also give necessary and sufficient conditions to obtain asymptotic efficiency under unanimous voting rules, and show that unanimous rules may lead to a bias in which moderate outcomes are never chosen.     

Endogenous agenda formation in three-person committees

This paper analyzes a 3-person voting game in which two or three players have the ability to choose alternatives to be considered. Once the set of possible alternatives and the structure of the voting procedure are known, the players can solve for the outcome. Thus, the actual choice over outcomes takes place in the choice of alternatives to be voted on, i.e., the agenda. An equilibrium to this agenda-formation game in shown to exist under different assumptions about the information relative to the order of the players in the voting game. Further, this equilibrium is computed and found to possess certain features which are attractive from a normative point of view.Prepared for delivery at the 1985 Annual Meeting of the American Political Science Association, The New Orleans Hilton, August 29–September 1, 1985. We would like to thank Richard McKelvey, Norman Schofield and two anonymous referees for valuable comments and suggestions. We retain responsibility for remaining errors.     

The Banks Set in Infinite Spaces

I provide a definition of the Banks set, or set of sophisticated voting outcomes, over an infinite policy space and when individual preferences are weak. I also show that the Banks set is a subset of one definition of the uncovered set, but not another. The interpretation of the Banks set in this setting differs from Banks’s original interpretation in the implicit role of the agenda setter. In addition, a characterization of the Banks set is provided for a three-player game of distributive politics. In this special setting, the Banks set and all definitions of the uncovered set have full measure over the space of alternatives.     

Recognizing majority-rule equilibrium in spatial voting games

It is provably difficult (NP-complete) to determine whether a given point can be defeated in a majority-rule spatial voting game. Nevertheless, one can easily generate a point with the property that if any point cannot be defeated, then this point cannot be defeated. Our results suggest that majority-rule equilibrium can exist as a purely practical matter: when the number of voters and the dimension of the policy space are both large, it can be too difficult to find an alternative to defeat the status quo. It is also computationally difficult to determine the radius of the yolk or the Nakamura number of a weighted voting game.We are grateful to Norman Schofield and an anonymous referee for many helpful suggestions.The first author was supported in part by a Presidential Young Investigator Award from the National Science Foundation (ECS-8351313) and by the Office of Naval Research (N00014-85-K-0147). The third author was supported in part by a Presendential Young Investigator Award from the National Science Foundation (ECS-8451032).     

Committees with Farsighted Voters: A New Interpretation of Stable Sets

The interpretation of von Neumann–Morgenstern stable sets in voting games has been debated by most political scientists. The present paper addresses the issue in a model that consists of an infinite sequence of repetitions of the standard committee game. The analysis of equilibrium processes leads to the following conclusion: when voters are farsighted, an alternative is the limit of an absorbing equilibrium process if and only if it belongs to some stable set of the underlying committee game. While the traditional interpretation of the core implicitly assumes myopic voters, we also demonstrate that the core of a strong committee is the unique limit of all absorbing equilibrium processes, provided that voters are arbitrarily patient. We finally proceed to an analysis of the Condorcet Paradox in this dynamic context.     

Voting games,indifference, and consistent sequential choice rules

We present four choice functions which characterize the stationary points of sequential search rules derived from a preference relation over outcomes. These functions are contrasted with others in the literature in terms of narrowness of choice as well as their ability to satisfy certain normative and consistency conditions, and it is shown how two of these sets arise as the set of equilibrium outcomes of a voting game under different tie-breaking assumptions.We would like to thank Nicholas Miller for introducing us and two anonymous referees for valuable comments and suggestions.     

Linear cost sharing in economies with non-Samuelsonian public goods: Core equivalence

 We consider an economy with non-Samuelsonian public goods and we focus on linear cost sharing. In a linear cost sharing equilibrium all agents in the economy optimize given a certain fixed cost share to be contributed towards the provision of public goods in the economy. Hence, each agent pays a certain fraction of the total establishment costs of public goods and these cost shares are common knowledge. We show that for a certain fixed contribution scheme the resulting linear cost share equilibria are equivalent to corresponding core allocations, in which the core is based on the integral of the individual cost shares. We also show that there is no equivalence of the Foley core with cost share equilibria, even in well-behaved large economies. Received: 16 August 1995/Accepted: 29 July 1996     

Contest with attack and defense: does negative campaigning increase or decrease voter turnout?

There are two ways of winning a competition, by increasing one’s own chances of winning or by decreasing those of one’s opponents. I consider a model of contest with attack and defense and propose an application to negative political campaigns, where two candidates choose between disparaging their opponent or valorizing their own image. I provide sufficient conditions for the existence and uniqueness of the symmetric Nash equilibrium of the contest game. Through this model, I then contribute to the controversy concerning the effect of negative campaigning on voter turnout.     

Freedom of choice in a social context: comparing game forms

In this paper, the set of outcomes of game forms is introduced as the relevant attribute for evaluating freedom of choice. These sets are defined as the cartesian product of every individual’s set of available options. It is argued that doing so is one way of taking into account social interactions when evaluating individual freedom. A set of axioms is introduced, each of which conveys some intuitions about how interactions affect freedom of choice, axioms by the mean of which two criteria, the Max and the MaxMin, are characterised for comparing game forms in terms of the freedom of choice they offer. These criteria are based, respectively, on the comparison of the best and the worst outcome the individual can reach in the game form.     

On strategy-proof social choice under categorization

I consider social choice problems such that (i) the set of alternatives can be partitioned into categories based on a prominent and objective feature and (ii) agents have strict preferences over the alternatives. Main results are characterizations of the structure of the strategy-proof social choice functions. I prove that each social choice function is strategy-proof if and only if it is decomposable into “small” strategy-proof social choice functions; one of them chooses one category and each of the others chooses one alternative from a category.     

Scoring rule voting games and dominance solvability

This article studies the dominance solvability (by iterated deletion of weakly dominated strategies) of general scoring rule voting games when there are three alternatives. The scoring rules we study include Plurality rule, Approval voting, Borda rule, and Relative Utilitarianism. We provide sufficient conditions for dominance solvability of general scoring rule voting games. The sufficient conditions that we provide for dominance solvability are in terms of one statistic of the game: sufficient agreement on the best alternative or on the worst alternative. We also show that the solutions coincide with the set of Condorcet Winners whenever the sufficient conditions for dominance solvability are satisfied. Approval Voting performs the best in terms of our criteria.     

LIVING IN TWO NEIGHBORHOODS—SOCIAL INTERACTION EFFECTS IN THE LABORATORY

Field evidence suggests that people belonging to the same group often behave similarly, that is, behavior exhibits social interaction effects. We conduct a laboratory experiment that avoids the identification problem present in the field and allows us to study the behavioral logic of social interaction effects. Our novel design feature is that each subject is simultaneously a member of two randomly assigned and identical groups where only members (“neighbors”) are different. We study behavior in a coordination game with multiple equilibria and a public goods game, which has only one equilibrium in material payoffs. We speak of social interactions if the same subject at the same time makes group‐specific decisions that depend on their respective neighbors' decisions. We find that a majority of subjects exhibit social interaction effects both when the game has multiple equilibria in material payoffs and when it only has one equilibrium. (JEL C91, H41, K42, H26)     

On enforcing socially best alternatives of binary group decision rules

We consider a large class of group decision rules based on pairwise comparisons. We show that if a socially best alternative is defined by the group decision rule, then one can devise a game form such that at least one such alternative can be realized under the appropriate notion of equilibrium.We are extremely grateful to G. Chichilinsky, P. Coughlin and an anonymous referee for helpful comments on earlier drafts of this paper     

Inefficient committees: small elections with three alternatives

We consider small committees which have to elect one of three alternatives using the simple plurality rule. Committee members have common, state-dependent preferences and receive imprecise private signals about the state of nature prior to the election. We are interested in whether the committee decision is efficient, that is whether the probability with which the committee elects the correct alternative is higher than the probability with which one single individual alone—on behalf of the others—would. It has been shown that there exists a unique efficient equilibrium in elections with two alternatives. We show that this result does not extend to elections with more alternatives. Multiple equilibria may exist for the same committee, and there may be both efficient and inefficient ones. Informative voting may or may not be an equilibrium. Also contrary to two-alternative elections, there exist responsive equilibria in which voters vote ‘against’ their signal. As a consequence, only two alternatives receive positive expected vote shares and the outcome is inefficient.     

On the (sequential) majority choice of public good size and location

This article studies majority voting over the size and location of a public good when voters differ both in income and in their preferences for the public good location. Public good provision is financed either by a lump sum tax or by a proportional income tax. We analyze both the simultaneous and the sequential determinations of the public good’s size and location. We show that, while the choice of the type of public good follows the traditional median logic, the majoritarian determination of the taxation rate need not coincide with the preferences of a median income citizen. With lump sum financing, income heterogeneity plays no role and the sequential equilibrium consists of the median location together with the public good level most-preferred by the individual located at the median distance from the median. This policy bundle also constitutes an equilibrium with simultaneous voting in the special case of a uniform bivariate distribution of individuals’ income and location. With proportional taxation, there is no policy equilibrium with simultaneous voting. We offer a complete characterization of the equations describing the sequential equilibrium in the general case and we show why and how our results depart from those most-preferred by the median income individual located at the median distance from the median. We also compare these majority voting allocations with the socially optimal one.     

Power indices expressed in terms of minimal winning coalitions

A voting situation is given by a set of voters and the rules of legislation that determine minimal requirements for a group of voters to pass a motion. A priori measures of voting power, such as the Shapley–Shubik index and the Banzhaf value, show the influence of the individual players in a voting situation and are calculated by looking at marginal contributions in a simple game consisting of winning and losing coalitions derived from the legislative rules. We introduce a new way to calculate these measures directly from the set of minimal winning coalitions and derive explicit formulae for the Shapley–Shubik and Banzhaf values. This new approach logically appealing as it writes measures as functions of the rules of the legislation. For certain classes of games that arise naturally in applications the logical shortcut drastically simplifies the numerical calculations to obtain the indices. The technique generalises directly to all semivalues.     

The structure of coalitional power under probabilistic voting procedures

We consider probabilistic voting procedures which map each feasible set of alternatives and each utility profile to a social choice lottery over the feasible set. It is shown that if we impose: (i) a probabilistic collective rationality condition known as regularity; (ii) probabilistic counterpart of Arrow's independence of irrelevant alternatives and citizens' sovereignty; (iii) a probabilistic positive association condition called monotonicity; then the coalitional power structure under a probabilistic voting procedure is characterized by weak random dictatorship. Received: 1 March 1999/Accepted: 21 May 2001     

Volunteering and the strategic value of ignorance

Private provision of public goods often takes place as a war of attrition: individuals wait until someone else volunteers and provides the good. After a certain time period, however, one individual may be randomly selected. If the individuals are uncertain about their cost of provision, but can find out about this cost ahead of the volunteering game, a strategic value is attached to the information, and individuals may prefer not to learn their cost of provision. If the time horizon is sufficiently short, in equilibrium only one individual may acquire information about his cost. For a long time horizon, acquiring information is strictly dominant. The time limit is an important instrument in influencing the efficiency of the volunteering game.