Bribe-proof Rules in the Division Problem

The division problem consists of allocating an amount of a perfectly divisible good among a group of n agents with single-peaked preferences. A rule maps preference profiles into n shares of the amount to be allocated. A rule is bribe-proof if no group of agents can compensate another agent to misrepresent his preference and, after an appropriate redistribution of their shares, each obtain a strictly preferred share. We characterize all bribe-proof rules as the class of efficient, strategy-proof, and weak replacement monotonic rules. In addition, we identify the functional form of all bribe-proof and tops-only rules.Bribe-proofness, Strategy-proofness, Efficiency, Replacement Monotonicity, Single-peakedness

A Maximal Domain of Preferences for Tops-only Rules in the Division Problem

The division problem consists of allocating an amount M of a perfectly divisible good among a group of n agents. Sprumont (1991) showed that if agents have single-peaked preferences over their shares, the uniform rule is the unique strategy-proof, efficient, and anonymous rule. Ching and Serizawa (1998) extended this result by showing that the set of single-plateaued preferences is the largest domain, for all possible values of M, admitting a rule (the extended uniform rule) satisfying strategy-proofness, efficiency and symmetry. We identify, for each M and n, a maximal domain of preferences under which the extended uniform rule also satisfies the properties of strategy-proofness, efficiency, continuity, and "tops-onlyness". These domains (called weakly single-plateaued) are strictly larger than the set of single-plateaued preferences. However, their intersection, when M varies from zero to infinity, coincides with the set of single-plateaued preferences.Strategy-proofness, single-plateaued preferences

On the Weights of Nations: Assigning Voting Weights in a Heterogenous Union

Consider a voting procedure where countries, states, or districts comprising a union each elect representatives who then participate in later votes at the union level on their behalf. The countries, provinces, and states may vary in their populations and composition. If we wish to maximize the total expected utility of all agents in the union, how to weight the votes of the representatives of the different countries, states or districts at the union level? We provide a simple characterization of the efficient voting rule in terms of the weights assigned to different districts and the voting threshold (how large a qualified majority is needed to induce change versus the status quo). Next, in the context of a model of the correlation structure of agents preferences, we analyze how voting weights relate to the population size of a country. We then analyze the voting weights in Council of the European Union under the Nice Treaty and the recently proposed constitution, and contrast them under different versions of our model.

An Assessment of How Urban Crime and Victimization Affects Life Satisfaction

We assess the effect of the homicide rate, individual´s perception of security in their neighborhood of residence, and of the effect of their having been victimized, on life satisfaction. We find a negative effect of the homicide rate on life satisfaction for the subsample of individuals living in their current houses for at least 10 years or more, who had moved to that place at some point in the past. We also find a positive and robust effect of the perception of security in the households´neighborhood for the whole sample, and for different subsamples considered. Having been victim of an offense is also robustly negatively related to life satisfaction, in particular in the cases where the offense was robbery.Quality of Life, Life Satisfaction, Crime. Classification JEL: I32, K40, K42.

Choosing How to Choose: Self-Stable Majority Rules and Constitutions

Constitutional arrangements affect the decisions made by a society. We study how this effect leads to preferences of citizens over constitutions; and ultimately how this has a feedback that determines which constitutions can survive in a given society. Constitutions are stylized here, to consist of a voting rule for ordinary business and possibly different voting rule for making changes to the constitution. We deffine an equilibrium notion for constitutions, called self-stability, whereby under the rules of a self-stable constitution, the society would not vote to change the constitution. We argue that only self-stable constitutions will endure. We prove that self-stable constitutions always exist, but that most constitutions (even very prominent ones) may not be self-stable for some societies. We show that constitutions where the voting rule used to amend the constitution is the same as the voting rule used for ordinary business are dangerously simplistic, and there are (many) societies for which no such constitution is self-stable rule. We conclude with a characterization of the set of self-stable constitutions that use majority rule for ordinary business.

LEARNING BY DOING IN AN AMBIGUOUS ENVIRONMENT

We experimentally test whether risk aversion or ambiguity aversion can explain decisions in a learning by doing game. We first measure subjects' preferences toward risk and ambiguity, and then use these measures to predict behavior in the game. We find that ambiguity averse subjects pay more often to resolve ambiguity in the game. We also find that less risk averse subjects earn more in the game. Our results, in light of a previous field study of rural farmers in a developing economy, suggest a link between ambiguity aversion and technology choice, as well as a link between risk aversion and farm profitability.

The provision of quality in a bilateral search market

We accomplish two goals. First, we provide a non-cooperative foundation for the use of the Nash bargaining solution in search markets. This finding should help to close the rift between the search and the matching-and-bargaining literature. Second, we establish that the diversity of quality offered (at an increasing price-quality ratio) in a decentralized market is an equilibrium phenomenon - even in the limit as search frictions disappear.quality dispersion, Nash Program, bilateral search

Stable Condorcet Rules

We consider the following allocation problem: A fixed number of public facilities must be located on a line. Society is composed of $N$ agents, who must be allocated to one and only one of these facilities. Agents have single peaked preferences over the possible location of the facilities they are assigned to, and do not care about the location of the rest of facilities. There is no congestion. In this context, we observe that if a public decision is a Condorcet winner, then it satisfies nice properties of internal and external stability. Though in many contexts and for some preference profiles there may be no Condorcet winners, we study the extent to which stability can be made compatible with the requirement of choosing Condorcet winners whenever they exist.Social Choice Correspondences, Condorcet Rules, Stability, Simpson Rule