Utilitarian Collective Choice and Voting

Game theoreticians usually deal with standard voting methods, such as plurality voting or approval voting. In reality however, some complicated non-standard voting methods are used. In this paper we shall present the voting method and rotation scheme used by the Governing Council of the European Central Bank (ECB), as it enlarges to accommodate new members of the economic and monetary union. We present game theoretical approaches to analyzing this method and different methods of computing the Shapley value for games connected with voting under such rotation schemes.

We use preference data from the 2015 parliament election in the Austrian federal state of Styria to analyze different voting rules. An exit poll right after the election collected data on ordinal and cardinal preferences from approximately 1000 actual voters. Our analysis is threefold. First, we determine the hypothetical social outcomes under different voting rules; second, we investigate the stability of the outcomes under those rules. Finally, we provide a categorization of different types of parties and analyze the impact of certain voting rules (Plurality Rule, Plurality Run Off, Hare System, Condorcet Method, Approval Voting, Borda Rule, Evaluative Voting, and Majority Judgment) on the performances of parties in those scenarios.

The paper summarizes two series of experiments demonstrating the cognitive properties of approval voting. The former series is devoted to mental processes induced in decision makers who use the method of approval voting. Based on cognitive effort, the use of choice strategies is presented in this paper. The observations of respondents show that most of them use relatively effortless strategy of eliminating alternatives and attributes. Few respondents use more sophisticated methods. The other series of experiments analyses the number of alternatives chosen in approval voting. It appears that the average number is not constant, even for similar votes but it depends on the subject of voting. The number of chosen alternatives and the subjective significance of the scope of voting are negatively or positively correlated in the case of special votes. The analyzed experiments show that the cognitive properties of approval voting have a diverse structure.

This paper combines social choice theory with mathematical optimization by applying various group decision concepts to a classical problem of combinatorial optimization, namely the famous traveling salesperson (sales- man) problem. The aim of the latter is to find a tour through all vertices of a given graph along edges of minimal total cost. In this contribution we replace the measure of additive edge costs by the social acceptance of different edges and the resulting tours. In particular, for four different voting rules, the Borda rule, Approval voting, Plurality rule and Simple Majority rule, we will investi- gate the social acceptance of tours derived from global and local decisions. It will be shown that these two decision approaches can lead to widely varying results.

By classic results in social choice theory, any reasonable preferential voting method sometimes gives individuals an incentive to report an insincere preference. The extent to which different voting methods are more or less resistant to such strategic manipulation has become a key consideration for comparing voting methods. Here we measure resistance to manipulation by whether neural networks of varying sizes can learn to profitably manipulate a given voting method in expectation, given different types of limited information about how other voters will vote. We trained over 100,000 neural networks of 26 sizes to manipulate against 8 different voting methods, under 6 types of limited information, in committee-sized elections with 5-21 voters and 3-6 candidates. We find that some voting methods, such as Borda, are highly manipulable by networks with limited information, while others, such as Instant Runoff, are not, despite being quite profitably manipulated by an ideal manipulator with full information. For the three probability models for elections that we use, the overall least manipulable of the 8 methods we study are Condorcet methods, namely Minimax and Split Cycle.

We have observed that some recent results cast serious doubts uponthe applicability of majority rule as a device for forming a group-willout of individual wills. On the other hand, majority rule has manyproperties to recommend it. Especially, the decisiveness propertyshould please anyone interested in efficiency considerations. How-ever, when it comes to the second major criterion, consistency, major-ity rule with pairwise comparison of alternatives often leads to diffi-culties. Indeed, we have seen that there is typically no core or Con-dorcet winner when the policy space is multidimensional real space.And when there is no core, the situation looks grim indeed for major-ity rule: literally any outcome may become the majority winner. Somerelief of this very strong result is provided by the fact that no majoritycycles can go through the outcomes that belong to the M2 bargainingset. This finding, of course, solves the problem facing majority rule onlyinsofar as a method can be devised by which the M2 bargaining set out-comes can be determined in a reliable way. Here, thus, we are con-fronted with the sincerity problem. The absence of the core can lead to chaotic trajectories of votingoutcomes in multidimensional space. However, there are ways of over-coming the difficulties if a sufficient amount of flexibility is allowedin institutional design. If we consider the various nonequilibrium solu-tion concepts, and the minimax set in particular, we can always designa decision rule which (under mild restrictions) makes the vote-maximiz-ing outcome trajectory enter the solution set. The flexibility needed isgreat, indeed: the decision rule, λ-majority, must be alterable for eachvoting situation. The determination of the winner in a pair-wise comparison of alter-natives is not the main source of the difficulties surrounding majorityrule. As a matter of fact, the method of building the agenda is the mostcrucial part of the problem of cyclical majorities. In multicandidatecontests the occurrence of cyclical majorities has motivated the studyof other.decision procedures in addition to the majority comparisonof alternatives. The most recent proposal, approval voting, is morestrategyproof than its competitors in the class of single-ballot, non-ranked voting systems. At the moment the relationships betweenapproval voting and majority rule are not clear. It seems that furtherstudy of the interrelationships of these procedures is called for. Thefeatures in which approval voting is superior to majority comparisonof pairs of alternatives, however, are not, strictly speaking, procedural,but are external to the method of making collective decisions.

For most of this nation's history, electoral democracy has consisted mainly of competition between the candidates of two major national parties. Thus in most elections for national office the present method of categorical voting, that is, voters vote for one candidate only, has served adequately. Except for the electoral college, this method satisfies a simple democratic criterion - the winner is prefferes to the loser by a simple majority of the voters.

Approval ballots provide an opportunity for agents to make a comment about every candidate, without incurring the overhead of determining a full ranking on the set of candidates; they are very natural for many practical settings. We study the computational complexity of the committee selection problem for several approval-based voting rules in the presence of outliers. Our first result shows that outliers render the committee selection problem intractable for approval, net approval, and minisum approval voting rules. We next study the parameterized complexity of this problem with five natural parameters, namely the target score, the size of the committee (and its dual parameter namely the number of candidates outside the committee); and the number of outliers (and its dual parameter namely the number of non-outliers). For approval, net approval, and minisum approval voting rules, we provide a dichotomous result, which resolves the parameterized complexity of this problem for all subsets of the above five natural parameters considered (by showing either fixed parameter tractability or W[1]-hardness for all subsets of parameters).

A variety of constructive manipulation, control, and bribery problems for approval-based multiwinner voting have been extensively studied recently. However, their destructive counterparts seem to be less explored. This article investigates the complexity of several destructive bribery problems under five prestigious approval-based multiwinner voting rules—approval voting, satisfaction approval voting, net-satisfaction approval voting, Chamberlin-Courant approval voting, and proportional approval voting. Broadly, these problems aim to determine if a number of given candidates can be excluded from any winning committees by performing a limited number of modification operations. We offer a complete landscape of the complexity of the problems. For NP -hard problems, we study their parameterized complexity with respect to meaningful parameters.

When choosing a voting rule to make subsequent decisions, the members of a committee may wish this rule to be self-selected when it is the object of a choice among a menu of different possible voting rules. Such concepts have recently been explored in Social Choice theory, and a menu of voting rule is said to be stable if it contains at least one self-selective voting rule at each profile of preferences on voting rules. We consider in this article the menu constituted by the three well-known scoring rules {Borda, Plurality, and Antiplurality}. Under the Impartial Culture assumption, which proposes an a priori model to estimate the likelihood of the profiles, we will derive a probability for the stability of this triplet of voting rules.

Blockchain technology is one of the fourth industrial revolution technologies that ensure traceability and transparency in recording electronic transactions. Though this technology has been applied in different domains such as finance, logistics and many more, its use in electoral system is yet to be fully realized. An electoral system hinges on fairness and transparency of voting processes. The traditional voting method involves the use of paper and ink system, manual vote counting and irregularities such as multiple voting, over-voting and delay in declaring election results. This results in a lack of trust and transparency in the voting processes. COVID-19 outbreak increased the pace of digitization in most fields, economic sectors and institutions. In this paper, we review the use of blockchain technology because it is a foundational technology that can ensure fairness in voting during general elections across the globe. We look at the case of Ghana’s electoral irregularities during the 2020 general elections. Ghana was chosen because it served as benchmark for most developing nations. Recent data were collected from an online data repository using keywords including blockchain technology, COVID-19 pandemic and conventional voting methods. The findings of the review suggest that during the year 2020 which witnessed the COVID-19 pandemic, no country in Africa adopted or implemented the blockchain technology in voting despite its ability to facilitate remote voting and curb the spread of the Coronavirus. This could be attributed to the fact that the COVID-19 outbreak took most nations by surprise and countries which have scheduled elections in 2020 did not budget for its use. The paper also provides shortcomings of the conventional voting methods and the capabilities of blockchain technology to address those shortcomings. These findings are imperative to form the electoral process of nations because of the underlying benefits of blockchain: ensuring transparency, auditability, traceability in processes, immutability and fairness.KeywordsBlockchain technologyCOVID-19 pandemicDemocracyElection credibilityE-voting

public choice theory to familiarize themselves with the masterworks in political theory. [6, 99-101] With this call for broader scholarship in mind, we were impressed in a recent reading of Aristotle's Politics with two aspects of his thought that, in our opinion, should be brought to the attention of modern scholars. First, we examine Aristotle's commentary on voting rules and propose a resolution of an important conflict in the literature interpreting his position on majority rule. Second, we examine Aristotle's general, but not unqualified, belief, presented mainly in analogies, that the collective wisdom of a people was superior to that of the lawgiver's. The main question that we address is whether this superior wisdom was to be embodied in the degree of restrictiveness in the voting rule or in the limits of suffrage. We show that under the former interpretation Aristotle hypothesized an important link between the restrictiveness of the voting rule and the amount of information that is brought to bear in making collective decisions. This is a link perhaps overlooked by modern writers on public choice, and we examine its effect in a model of the optimal voting rule, originally developed by J. M. Buchanan and G. Tullock, to observe its impact on the minimum cost decision rule. [7, 63-84]

In this conference we celebrate the 50th anniversary of the publication of "Social Choice and Individual Values" by Kenneth Arrow [14]. Fyodor Dostoevski once said that the literature of the second half of the 19th century grew out of Nikolai Gogol's short novel, "An Overcoat." To paraphrase Dostoevski, we can say that the theory of social choice after 1951 grew out of "Social Choice and Individual Values." Although social decisions are universal, very little work was completed in Russia and the Soviet Union on the theoiy of social choice up until recent times. Thus I am first going to discuss briefly the histoiy of social choice in Russia. I restrict myself to the period up to 1 991 , since I believe this was the year in which a new era in Russian history began. The development of social choice after 1991 is a subject for future investigation.

PurposeIn this study the authors aim to comprehensively investigate the determinants of voting behavior in Turkey, with a specific focus on the dynamics of the center-periphery debate. Mainly, the authors focus on regional voting patterns during the period that is dominated by the Justice and Development Party (JDP/AKP) in the elections. The authors apply the random effects generalized least squares (GLS) methodology, and analyze electoral data covering four pivotal parliamentary elections (2007, 2011, 2015 and 2018) across all 81 provinces (NUTS III regions). The authors individually examine voting dynamics of the four major parties in parliament: the JDP/AKP, the Republican People's Party (RPP/CHP), the Nationalist Movement Party (NMP/MHP) and the Peoples' Democratic Party (PDP/HDP). The authors contribute to a comprehensive understanding of how socioeconomic cleavages, economic performance, party alignment and social dynamics shape voter preferences in the Turkish context, thereby addressing gaps in the existing literature.Design/methodology/approachThis research employs an ecological study of Turkish NUTS III sub-regions, covering national elections from 2007 to 2018. The authors utilize the random effects GLS method to account for heteroscedasticity and time effects. The inclusion of the June and November 2015 elections enables a comprehensive analysis of the evolving dynamics in Turkish voting behavior. The results remain robust when applying pooled OLS and fixed effect OLS techniques for control.FindingsThe study's findings reveal that economic performance, specifically economic growth, plays a pivotal role in the sustained dominance of the JDP/AKP party. Voters closely associate JDP preference with economic growth, resulting in higher voting shares during periods of economic prosperity. Along with economic growth; share of agriculture in regions' GDP, female illiteracy rate, old population rate, net domestic migration, terrorism and party alignment are also influential factors in the Turkish case. Furthermore, differences among sociocultural groups, and East–West dichotomy seem to be important factors that reveal the impact of social cleavages to understand electoral choice in Turkey.Originality/valueThis study contributes to the existing literature by offering a comprehensive multidimensional analysis of electoral behavior in Turkey, focusing on the JDP/AKP dominance period. The main contribution of this study is its multidimensional perspective on the power bases of all main parties, considering key voter choice theories (cleavages, party alignment and retrospective economic performance voting) that have not been systematically analyzed in prior research. The main research question of this study is to examine which factors affect voting behavior in Turkey and how the dynamics of center-periphery or eastern-western region voting behavior under the JDP hegemony can be explained. The contribution of this study consists not only in its empirical testing of panel data approaches but also in its comprehensive analysis of four major political parties. Building upon existing studies in the literature, this research seeks to extend the understanding of voting dynamics for the four main parties in the parliament — JDP/AKP, RPP/CHP, NMP/MHP and PPDP/HDP — by delving into their dynamics individually, thereby expanding the scope of previous studies. This study aims to make a contribution by not only empirically testing panel data approaches but also conducting a comprehensive analysis of four major political parties. Furthermore, the separate inclusion of the 2015 elections and utilization of a panel data approach enrich the analysis by capturing the evolving dynamics of Turkish voting behavior. The study underscores the significance of socioeconomic factors, economic performance and social cleavages for voters' choices within the context of a dominant party rule.

In April 2017, during the first round of the French presidential election, we performed a set of experiments on the use of voting rules. Participants to these experiments were asked to test several alternative voting methods, like approval voting, and other variants of evaluative voting. The experiments were both carried out in situ in polling stations during the first round of the presidential election (using paper ballots), and on line during the month preceding the first round, and until the second round of the election (using a web application). A total of 6358 participants took part to the in situ experiment and 37739 participants took part to the on line experiment. This paper describes the protocol of the in situ experiments and the format of the collected dataset