New Economics Papers
on Collective Decision-Making
Issue of 2009‒06‒03
seven papers chosen by

  1. In Silico Voting Experiments By Jean-François Laslier
  2. Plurality versus proportional electoral rule: study of voters' representativeness By Amedeo Piolatto
  3. Stable Coalition-Governments: The Case of Three Political Parties By M. Socorro Puy
  4. Focused Power: Experimental Manifestation of the Shapley-Shubik Power Index By Chris Geller; Jamie Mustard; Ranya Shahwan
  5. Picking the Winners By Pablo Amorós
  6. Genetic Variability and Collective Social Norms: The Case of Binge Drinking By Shogren, Jason F.; Nævdal, Eric
  7. Evaluating Consensus Forecasts By Herman O. Stekler

  1. By: Jean-François Laslier (Department of Economics, Ecole Polytechnique - CNRS : UMR7176 - Polytechnique - X)
    Abstract: This paper presents computer simulations of voting rules: Plurality rule, Approval voting and the Copeland and Borda rules, with voters voting sincerly or strategically. Different ways of generating random preference profiles are introduced: Rousseauist cultures are suitable for common interest project assessment; Impartial cultures are standard in Social Choice Theory; Distributive cultures and Spatial Euclidean ones are standard in Political Science.
    Keywords: Social Choice. Voting Rules. Impartial Culture. Condorcet. Borda
    Date: 2009–06–02
  2. By: Amedeo Piolatto (Universidad de Alicante)
    Abstract: Thinking of electoral rules, common wisdom suggests that proportional rule is more fair, since all voters are equally represented: at times, it turns out that this is false. I study the formation of both Parliament and Government; for the composition of the former I consider plurality and proportional rule; for the formation of the latter, I assume that parties play a non-cooperative game à la Rubinstein. I show that, unless parties are impatient to form a Government, proportional electoral rules translate into a more distortive distribution of power among parties than plurality rule; this happens because of the bargaining power of small parties during Government formation.
    Keywords: electoral systems, proportional rule, plurality rule, voters¿ representation.
    JEL: C71 D72 H1 P16
    Date: 2009–01
  3. By: M. Socorro Puy (Department of Economic Theory, Universidad de Málaga)
    Abstract: We explore to what extent we can propose fixed negotiation rules as well as simple mechanisms (or protocols) that guarantee that politi¬cal parties can form stable coalition-governments. We analyze the case where three parties can hold office in the form of two-party coalitions. We define the family of Weighted Rules, that select political agree¬ments as a function of the bliss-points of the parties, and electoral results (Camson's Law and equal-share among others are included). We show that every weighted rule yields a stable coalition. We make use of the theory of implementation to design a protocol (in the form of a mechanism) that guarantees that a stable coalition will govern. We find that no dominant-solvable mechanism can be used for this purpose, but there is a simultaneous-unanimity mechanism that im¬plements it in Nash and strong Nash equilibrium.
    Keywords: Coalition-government, Stability, Nash-implementation
    JEL: D71 D72
    Date: 2009–06
  4. By: Chris Geller (Deakin University); Jamie Mustard (Deakin University); Ranya Shahwan
    Abstract: Experiments evaluate the fit of the Shapley-Shubik Power Index to a controlled human environment. Subjects with differing votes divide a fixed purse by majority rule in online chat rooms under supervision. Earnings serve as a measure of power. Chat rooms and processes for selecting subjects reduce or eliminate extraneous political forces, leaving logrolling as the primary political force. Initial proposals by subjects for division of the purse allow measurement of effects from focal points and transaction costs. Net results closely fit the Shapley-Shubik Power Index.
    Keywords: Voting, Power Index, Focal Point, Shapley-Shubik, Experiment
    JEL: C71 C78 C92
    Date: 2007–11–23
  5. By: Pablo Amorós (Department of Economic Theory, Universidad de Málaga)
    Abstract: We analyze the problem of choosing the w contestants who will win a competition within a group of n>w competitors when all jurors commonly observe who are the w best contestants but may be biased. We study conditions on the configuration of the jury so that it is possible to induce the jurors to always choose the best contestants, whoever they are. If the equilibrium concept used by the jurors is dominant strategies, the necessary and sufficient conditions incorporate very strong informational requirements on the mechanism designer. If we relax the equilibrium concept to Nash or subgame perfect equilibria the necessary and sufficient conditions are less demanding. Moreover, these conditions are also necessary for any other equilibrium concept. Finally, we study one specific application: we propose a simple and natural mechanism for the case where each juror is biased in favor of one and only one (different) contestant.
    Keywords: Mechanism design, Social choice
    JEL: C72 D71 D78
    Date: 2009–06
  6. By: Shogren, Jason F. (Department of Economics and Finance); Nævdal, Eric (Department of Economics and HERO)
    Abstract: This paper explores how collective social norms can have individual-level genetic foundation. Our study is the first we know to report a plausible link between genetically founded individual preferences in a fraction of a population and social norms governing behavior of all individuals. As our motivating example, we focus on patterns of Excessive Drinking in Social Situations (EDSS) across Europe that are possibly triggered by genetically caused variations in personality. The genetic trait is shyness, which correlates with eye color. We present empirical results indicating that alcohol consumption in social situations correlate with eye color and a model which suggests that conditions exist in which EDSS can emerge as a strategy in a larger fraction of the population than is genetically predisposed to EDSS. In addition, our model shows that alcohol taxes may be counter-productive in controlling the emergence of EDSS as a social norm.
    Keywords: Excessive Drinking in Social Situations (EDSS); drinking behavior; genetically founded individual preferences; sosial norms
    JEL: I12 I18
    Date: 2009–06–04
  7. By: Herman O. Stekler (Department of Economics The George Washington University)
    Abstract: The Census Bureau makes periodic long-term forecasts of both the total US population and the population of each of the states. Previous evaluations of these forecasts were based on the magnitude of the discrepancies between the projected and actual population figures. However, it might be inappropriate to evaluate these long-term projections with the specific quantitative statistics that have been useful in judging short-term forecasts. One of the purposes of a long range projection of each state¡¯s population is to provide a picture of the distribution of the aggregate US population among the various states. Thus the evaluation should compare the projected distribution of the total US population by states to the actual distribution. This paper uses the dissimilarity index to evaluate the accuracy of the Census projected percentage distributions of population by states.
    Date: 2008–07

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