Stable Voting

JOURNAL OF POWER, POLITICS & GOVERNANCE, 2018

Under the present electoral system every citizen is entitled to voting for only one political party. However, pluralism is a cornerstone notion for democracies and consequently, when voters are entitled to voting for more than one political party, their option tends to extend on the grounds that they are provided with the capability of expressing their opinion holistically and are not confined to a single option. Such a method could be a point system, where each voter possesses a sum of points which are distributed in accordance with the voter's preferences. Consequently, this electoral system could be named "Preference -Point-Based Electoral System" (henceforth PPBES) and it should be noted that current developed would facilitate the existence of the aforementioned electoral system. The present paper aims at presenting a new electoral system, where voters are entitled to multiple options voting for.

2009

In this paper, we expose the results of a voting experiment realised in 2007, during the French Presidential election. This experiment aimed at confronting the Single Transferable vote (SVT) procedure to two criteria : simplicity and the selection of a Condorcet-winner. Building on our electoral sample's preferences, we show that this voting procedure can design a different winner, depending on the vote counting process. With the vote counting process advocated by Hare, the winner is Nicolas Sarkozy, while the Coombs vote counting process has François Bayrou as winner. For these two vote counting processes, the details of the experiment are the same and it is shown that the simplicity criterion is respected. However, with regard to the Condorcet-winner criterion, the Coombs methods is the only one to elect the Condorcet-winner, i.e. François Bayrou.

2019

This dissertation focuses on voting with partial preferences in the form of top-k ballots. We study ways to minimize the amount of communication required to approximate or to output the correct winner from truncated ballots with respect to different voting rules and we propose and analyze different methods allowing a compromise between the accuracy of the result and the amount of communication required; some require only one round of communication, while others are interactive. First, we assume that voters give, in a single shot, their top-k alternatives (for a fixed k); we define a version of voting rules (Borda, Harmonic, Copeland, Maximin, ranked pairs and STV) that works for such k-truncated votes. We consider two measures of the quality of the approximation: the probability of selecting the same winner as the original rule, and the score ratio. We do a worst-case study (for the latter measure only), and for both measures, an average-case study and a study from real data sets. A...

Proponents of Condorcet voting face the question of what to do in the rare case when no Condorcet winner exists. Recent work provides compelling arguments for the rule that should be applied in three-candidate elections, but already with four candidates, many rules appear reasonable. In this paper, we consider a recent proposal of a simple Condorcet voting method for Final Four political elections. Our question is what normative principles could support this simple form of Condorcet voting. When there is no Condorcet winner, one natural principle is to pick the candidate who is closest to being a Condorcet winner. Yet there are multiple plausible ways to define closeness, leading to different results. Here we take the following approach: identify a relatively uncontroversial sufficient condition for one candidate to be closer than another to being a Condorcet winner; then use other principles to help settle who wins in cases when that condition alone does not. We prove that our principles uniquely characterize the simple Condorcet voting method for Final Four elections. This analysis also points to a new way of extending the method to elections with five or more candidates that is simpler than an extension previously considered. The new proposal is to elect the candidate with the most head-to-head wins, and if multiple candidates tie for the most wins, then elect the one who has the smallest head-to-head loss. We provide additional principles sufficient to characterize this simple method for Final Five elections.

Annals of the New York Academy of Sciences, 1990

Artificial Intelligence and Law, 2007

Numerous countries are heading toward digital infrastructures. In particular this new technology promises to help support methods for elections. However, one should be careful that such an infrastructure does not hinder the voting and representation issues. On the contrary, it should support those issues and help citizens have a clearer picture of the underlying mechanisms. This paper deals with the limits of voting procedures as they are described in classical collective choice theory and reflects on ways to aggregate electronic votes stemming from various individuals that would be at the same time democratic, decisive and rational which is not feasible when candidate rankings alone are taken into account. This paper shows how electronic voting procedures could improve the situation by introducing preference-based votes.

2016

We present an alternative voting system that aims at bridging the gap between proportional representative systems and majoritarian, single winner election systems. The system lets people vote for multiple parties, but then assigns each ballot to a single party. This opens a whole range of possible systems, all representative. We show theoretically that this space is convex. Then among the possible parliaments we present an algorithm to produce the most majoritarian result. We then test the system and compare the results with a pure proportional and a majoritarian voting system showing how the results are comparable with the majoritarian system. Then we simulate the system and show how it tends to produce parties of exponentially decreasing size with always a first, major party. Finally we describe how the system can be used in a context of a parliament made up of two separate houses.

Applied Mathematics and Computation, 2004

This paper deals with a recently proposed method for a ranked voting system. It is based on a data envelopment analysis model. It is shown that the number of problems to be solved and the number of constraints in the model can be decreased. In addition, the winner can be selected with a fewer efforts and in some cases without solving any problems. The obtained results also illustrate the importance of selecting a proper norm in the model.

3rd International Conference on Information Security and Artificial Intelligenc, 2012

In almost all forms of government, voting holds an important role in selecting the winner who could be the head of the department, state or the country. In those states in which preferential voting takes place, the selection of winner becomes a tedious task. There are many algorithms or methods available for preferential voting systems but all of them fail in at least one of the fourteen recognized criterions. Some behavioral strategies exist which can hamper the solution of the selection methods. These strategies cover all those tricks applied by the politicians around the world to increase their chances of winning the election. These tricks can be of the form of manipulation, control or bribery. In order to predict the right winner of the election, we tried to make an algorithm which make use of some the existing methods or algorithms. The algorithm takes into account the number of criterions satisfied by that particular method. It also calculates the effect of complexity of behavioral strategies and the available theorems which can diminish that effect on the selection methods. Our algorithm makes a weighted graph of all the candidates on the basis of the individual weights calculated using the above mentioned factors and then select the most preferred candidate as the winner of the preferential elections.

2007

Although recent years have seen a surge of interest in the computational aspects of social choice, no attention has previously been devoted to elections with multiple winners, e.g., elections of an assembly or committee. In this paper, we fully characterize the worst-case complexity of manipulation and control in the context of four prominent multi-winner voting systems. Additionally, we show that several tailor-made multi-winner voting schemes are impractical, as it is N P-hard to select the winners in these schemes.