Weighted Proportional Losses Solution

We propose and characterize a new solution for problems with asymmetric bargaining power among the agents that we named weighted proportional losses solution. It is specially interesting when agents are bargaining under restricted probabilistic uncertainty. The weighted proportional losses assigns to each agent losses proportional to her ideal utility and also proportional to her bargaining power. This solution is always individually rational, even for 3 or more agents and it can be seen as the normalized weighted equal losses solution. When bargaining power among the agents is equal, the weighted proportional losses solution becomes the Kalai-Smorodinsky solution. We characterize our solution in the basis of restricted monotonicity and restricted concavity. A consequence of this result is an alternative characterization of Kalai-Smorodinsky solution which includes contexts with some kind of uncertainty. Finally we show that weighted proportional losses solution satisfyies desirable properties as are strong Pareto optimality for 2 agents and continuity also fulfilled by Kalai-Smorodinsky solution, that are not satisfied either by weighted or asymmetric Kalai-Smorodinsky solutions.

Additive adjudication of conflicting claims

In a “claims problem” (O’Neill 1982), a group of individuals have claims on a resource but its endowment is not sufficient to honour all of the claims. We examine the following question: If a claims problem can be decomposed into smaller claims problems, can the solutions of these smaller problems be added to obtain the solution of the original problem? A natural condition for this decomposition is that the solution to each of the smaller problems is non-degenerate, assigning positive awards to each claimant. We identify the only consistent and endowment monotonic adjudication rules satisfying this property; they are generalizations of the canonical “constrained equal losses rule” sorting claimants into priority classes and distributing the amount available to each class using a weighted constrained equal losses rule. The constrained equal losses rule is the only symmetric rule in this family of rules

Weighted proportional losses solution

We propose and characterize a new solution for problems with asymmetric bargaining power among the agents that we named weighted proportional losses solution. It is specially interesting when agents are bargaining under restricted probabilistic uncertainty. The weighted proportional losses assigns to each agent losses proportional to her ideal utility and also proportional to her bargaining power. This solution is always individually rational, even for 3 or more agents and it can be seen as the normalized weighted equal losses solution. When bargaining power among the agents is equal, the weighted proportional losses solution becomes the Kalai-Smorodinsky solution. We characterize our solution in the basis of restricted monotonicity and restricted concavity. A consequence of this result is an alternative characterization of Kalai-Smorodinsky solution which includes contexts with some kind of uncertainty. Finally we show that weighted proportional losses solution satisfyies desirable properties as are strong Pareto optimality for 2 agents and continuity also fulfilled by Kalai-Smorodinsky solution, that are not satisfied either by weighted or asymmetric Kalai-Smorodinsky solutions

Welfarism in specific economic domain

In economies with public goods, and agents with quasi-linear preferences, we give a characterization of the welfare egalitarian correspondence in terms of three axioms: Pareto optimality, symmetry and solidarity. This last property requires that an improvement in the ability to exploit the public goods of some of the agents not decrease the welfare of any of them.Public goods, welfare egalitarian

CULTURAL AND RISK-RELATED DETERMINANTS OF GENDER DIFFERENCES IN ULTIMATUM BARGAINING

We study culture and risk aversion as causes of gender differences in ultimatum bargaining. It has often been conjectured in the literature that gender differences in bargaining experiments are partly due to differences in risky decision making. Using the data obtained from our experimental sessions with Spanish subjects, we are able to disentangle risk-related and genuinely gender-specific effects in ultimatum games framed as salary negotiation between an employer and an employee. First, we confirm the broadly accepted result that women are more risk averse than men. Gender differences in both employer and employee-subjects' behavior remain significant after risk attitudes are accounted for. In fact, we show that the reported gender differences are not because of but rather despite females' higher risk aversion. Gender effects are found to depend also on cultural differences. Greek and Spanish females reject more and offer lower wages than males. British subjects exhibit gender effects only with respect to employee behavior, but the sign of the effect is opposite to that observed in the case of Greece and Spain.Ultimatum bargaining, salaries, gender, risk attitudes, experiments

El papel de los rendimientos y la diferenciación de productos como determinantes de la estabilidad del cártel

Estudiamos las implicaciones que tienen sobre la estabilidad del cártel, los rendimientos de la producción en presencia de productos diferenciados, cuando las empresas compiten en cantidades. Mostramos que el cártel puede ser igualmente estable en presencia de un menor grado de diferenciación siempre que las deseconomías de escala sean mayores. Además demostramos que a partir de un determinado factor de descuento pueden existir tecnologías con rendimientos de escala constantes o decrecientes donde el cártel siempre es estable independiente del grado de diferenciaciónWe study cartel stability in a differentiated quantity-setting duopoly with decreasing returns to scale. We show that a cartel may be equally stable in the presence of lower differentiation, provided that the decreasing returns parameter is higher. Furthermore, we show that, above a given discount rate, a cartel may be stable for any degree of product differentiatio

¿Por qué los mercados grandes no regulan?

El objetivo de este trabajo es estudiar, utilizando un modelo teórico, el impacto que el tamaño del mercado tiene sobre la regulación de las emisiones consecuencia de la actividad productiva de las empresas. En nuestro modelo asumimos dos países con mercados del mismo tamaño. En cada país opera una sola empresa que produce tanto para el mercado doméstico como el mercado extranjero. Los gobiernos deciden controlar las emisiones resultantes de la actividad productiva de las empresas gravándolas con un impuesto y dar así incentivos a las empresas a invertir en actividades de I+D con el fin de reducir sus emisiones. En un contexto en el que tanto las empresas como los gobiernos actúan de forma estratégica demostramos que un aumento en el tamaño del mercado reduce los incentivos de los gobiernos a aplicar impuestos a la contaminación.This paper aims to analyse, through the application of a theoretical model, the impact that the size of markets has on the regulations over the resulting emissions of the production activity of companies. In our model we acknowledge two countries with similar size markets. In each country there is just one operating company, producing both for the domestic and the foreign market. The governments decide to control the abovementioned emissions by introducing a tax, while, at the same time, incentives are given to those companies in order for them to invest in R&D and thus reduce their emissions. In a context where both the companies and the governments assume strategic roles we prove that an increase in the size of the market reduces the incentives governments grant regarding the introduction of taxes against pollution

Ethical allocation of scarce vaccine doses: The Priority-Equality protocol

Background: Whenever vaccines for a new pandemic or widespread epidemic are developed, demand greatly exceeds the available supply of vaccine doses in the crucial, initial phases of vaccination. Rationing protocols must then fulfill a number of ethical principles balancing equal treatment of individuals and prioritization of at-risk and instrumental subpopulations. For COVID19, actual rationing methods used a territory-based first allocation stage based on proportionality to population size, followed by locally-implemented prioritization rules. The results of this procedure have been argued to be ethically problematic. Methods: We use a formal-analytical approach arising from the mathematical social sciences which allows to investigate whether any allocation methods (known or unknown) fulfill a combination of (ethical) desiderata and, if so, how they are formulated algorithmically. Results: Strikingly, we find that there exists one and only one method that allows to treat people equally while giving priority to those who are worse o. We identify this method down to the algorithmic level and show that it is easily implementable and it exhibits additional, desirable properties. In contrast, we show that the procedures used during the COVID-19 pandemic violate both principles. Conclusions: Our research delivers an actual algorithm that is readily applicable and improves upon previous ones. Since our axiomatic approach shows that any other algorithm would either fail to treat people equally or fail to prioritize those who are worse o, we conclude that ethical principles dictate the adoption of this algorithm as a standard for the COVID-19 or any other comparable vaccination campaigns

Ethical allocation of scarce vaccine doses: the Priority-Equality protocol

Background: Whenever vaccines for a new pandemic or widespread epidemic are developed, demand greatly exceeds the available supply of vaccine doses in the crucial, initial phases of vaccination. Rationing protocols must then fulfill a number of ethical principles balancing equal treatment of individuals and prioritization of at-risk and instrumental subpopulations. For COVID-19, actual rationing methods used a territory-based first allocation stage based on proportionality to population size, followed by locally-implemented prioritization rules. The results of this procedure have been argued to be ethically problematic. Methods: We use a formal-analytical approach arising from the mathematical social sciences which allows to investigate whether any allocation methods (known or unknown) fulfill a combination of (ethical) desiderata and, if so, how they are formulated algorithmically. Results: Strikingly, we find that there exists one and only one method that allows to treat people equally while giving priority to those who are worse off. We identify this method down to the algorithmic level and show that it is easily implementable and it exhibits additional, desirable properties. In contrast, we show that the procedures used during the COVID-19 pandemic violate both principles. Conclusions: Our research delivers an actual algorithm that is readily applicable and improves upon previous ones. Since our axiomatic approach shows that any other algorithm would either fail to treat people equally or fail to prioritize those who are worse off, we conclude that ethical principles dictate the adoption of this algorithm as a standard for the COVID-19 or any other comparable vaccination campaigns

COST MONOTONIC MECANISMS

We study the existence of cost monotonic selections of the core in economies with several public goods. Under quasilinear utilities there is a cost inonotonic core selection mechanism if and only if the agents order the bundles of public goods equally. If this is indeed the case, any such mechanism must choose an egalitarian equivalent allocation. The equal ordering property is no longer required in the case of economies with quasi-linear separable utility functions and separable costs. In this set up, there is essentially only one cost monotoiiic mechanism. Furthermore, it has to select an egalit arian equivalent allocation.Public good, cost monotonicity, core, egalit arian equivalent allocations