SCORING RULE VOTING GAMES AND DOMINANCE SOLVABILITY

This paper studies the dominance-solvability (by iterated deletion of weakly dominated strategies) of general scoring rule voting games. The scoring rules we study include Plurality rule, Approval voting, Negative Plurality Rule, Borda rule and Relative Utilitarianism. We provide a classification of scoring rule voting games according to whether the sufficient conditions for dominance solvability require sufficient agreement on the best alternative or on the worst alternative. We also characterise the solutions when the sufficient conditions for dominance solvability are satisfied.Scoring Rules ; Voting Games ; Dominance Solvability ; Iterated Weak Dominance ; Condorcet Winner

Scoring rule voting games and dominance solvability

This paper studies the dominance-solvability (by iterated deletion of weakly dominated strategies) of general scoring rule voting games. The scoring rules we study include Plurality rule, Approval voting, Negative Plurality Rule, Borda rule and Relative Utilitarianism. We provide a classification of scoring rule voting games according to whether the sufficient conditions for dominance solvability require sufficient agreement on the best alternative or on the worst alternative. We also characterise the solutions when the sufficient conditions for dominance solvability are satisfied

Maximum Sustainable Government Debt in the Overlapping Generations Model.

The theoretical determinants of maximum sustainable government debt are investigated using Diamond's overlapping-generations model. A level of debt is defined to be 'sustainable' f a steady state with non-degenerate values of economic variables exists. We show that a maximum sustainable level of debt almost always exists. Most interestingly, it normally occurs at a 'catastrophe' ather than a 'degeneracy' , i.e. where variables such as capital and consumption are in the interiors, rather than at the limits, of their economically meaningful ranges. This means that if debt is increased step by step, the economy may suddenly collapse without obvious warning.GOVERNMENT DEBT ; OVERLAPPING GENERATIONS

When are plurality rule voting games dominance-solvable?

This paper studies the dominance-solvability (by iterated deletion of weakly dominated strategies) of plurality rule voting games. For K > 3 alternatives and n > 3 voters, we find sufficient conditions for the game to be dominance-solvable (DS) and not to be DS. These conditions can be stated in terms of only one statistic of the game, the largest proportion of voters who agree on which alternative is worst in a sequence of subsets of the original set of alternatives. When n is large, “almost all” games can be classified as either DS or not DS. If the game is DS, a Condorcet Winner always exists when n > 4, and the outcome is always the Condorcet Winner when the electorate is sufficiently replicate

The basic approval voting game

We survey results about Approval Voting obtained within the standard framework of game theory. Restricting the set of strategies to undominated and sincere ballots does not help to predict Approval Voting outcomes, which is also the case under strategic equilibrium concepts such as Nash equilibrium and its usual refinements. Strong Nash equilibrium in general does not exist but predicts the election of a Condorcet winner when one exists

The Trembling Chairman Paradox

The Chairman Paradox (Farquharson, 1969) is a classical observation in voting games showing that a Chairman endowed with tie-breaking power might end up with her worst outcome. The analysis posits three players whose preferences build a Condorcet cycle and invokes Iterated Elimination of Weakly Dominated Strategies (IEWDS) to select a unique equilibrium. However, IEWDS is a controversial procedure which exhibits well-known weaknesses. This work relies on non-controversial equilibrium refinements instead. For any cardinal payoffs representing the preferences, two pure-strategy equilibria are trembling-hand perfect, the paradoxical one and another one where the Chairman attains her best outcome. The original paradox is restored (and shown not to actually depend on IEWDS) if one considers the stronger concept of proper equilibrium. The analysis casts new light on a classical paradox and illustrates the difference between properness and trembling-hand perfection in a relevant example

Mechanisms for Making Accurate Decisions in Biased Crowds

Abstract This paper studies procedures for identifying the true answer to a binary question using the opinions of potentially-biased individuals. It's common and natural to side with the majority opinion, but the majority may make the wrong choice when the agents are biased. Taking majority rule as a baseline, I study peer-prediction decision rules, which ask agents to predict the opinions of others in addition to providing their own. This extra information enables us to potentially recognize the correct answer even when the majority is wrong. I first show that peer-prediction rules cannot be more accurate than the majority when we require them to satisfy the same symmetry conditions as majority rule and to be incentive-compatible for agents who intend to push the final decision towards their own opinion. Realistically though, not all agents distort their information strategically. I provide a simple decision rule based on the median agent's prediction that matches majority rule when all agents are strategic and makes more accurate decisions than majority rule when some agents are honest