Inequality-averse Preferences Research Articles

Other-regarding preferences and giving decision in a risky environment: experimental evidence

We investigate whether and how an individual giving decision is affected in risky environments in which the recipient’s wealth is random. We demonstrate that, under risk neutrality, the donation of dictators with a purely ex post view of fairness should, in general, be affected by the riskiness of the recipient’s payoff, while dictators with a purely ex ante view should not be. Furthermore, we observe that some influential inequality aversion preferences functions yield opposite predictions when we consider ex post view of fairness. Hence, we report on dictator games laboratory experiments in which the recipient’s wealth is exposed to an actuarially neutral and additive background risk. Our experimental data show no statistically significant impact of the recipient’s risk exposure on dictators’ giving decisions. This result appears robust to both the experimental design (within subjects or between subjects) and the origin of the recipient’s risk exposure (chosen by the recipient or imposed on the recipient). Although we cannot sharply validate or invalidate alternative fairness theories, the whole pattern of our experimental data can be simply explained by assuming ex ante view of fairness and risk neutrality.

Identity and Redistribution: Theory and Evidence

We propose a theoretical model that embeds social identity concerns, as in Akerlof and Kranton (2000), with inequity averse preferences, as in Fehr and Schmidt (1999). We conduct an artefactual ultimatum game experiment with registered members of British political parties, for whom political identity is salient and redistribution is also likely to be salient. The empirical results are as follows. (1) Proposers and responders demonstrate ingroup‐favouritism. (2) Proposers exhibit quantitatively stronger social identity effects relative to responders. (3) As redistributive taxes increase, average offers by proposers and the average minimum acceptable offers of responders (both as a proportion of income) decline by almost the same amount, suggesting a shared understanding that is characteristic of social norms. (4) Subjects experience less disadvantageous inequity from ingroup members relative to outgroup members.

Solution approaches for equitable multiobjective integer programming problems

We consider multi-objective optimization problems where the decision maker (DM) has equity concerns. We assume that the preference model of the DM satisfies properties related to inequity-aversion, hence we focus on finding nondominated solutions in line with the properties of inequity-averse preferences, namely the equitably nondominated solutions. We discuss two algorithms for finding good subsets of equitably nondominated solutions. The first approach is an extension of an interactive approach developed for finding the most preferred nondominated solution when the utility function is assumed to be quasiconcave. We find the most preferred equitably nondominated solution when the utility function is assumed to be symmetric quasiconcave. In the second approach we generate an evenly distributed subset of the set of equitably nondominated solutions to be considered further by the DM. We show the computational feasibility of the two algorithms on equitable multi-objective knapsack problem, in which projects in different categories are to be funded subject to a limited budget. We perform experiments to show and discuss the performances of the algorithms.

Identity and Redistribution: Theory and Evidence

We propose a theoretical model that embeds social identity concerns, as in Akerlof and Kranton (2000), with inequity averse preferences, as in Fehr and Schmidt (1999). We conduct an artefactual ultimatum game experiment with registered members of British political parties, for whom political identity is salient and redistribution is also likely to be salient. The empirical results are as follows. (1) Proposers and responders demonstrate ingroup-favoritism. (2) Proposers exhibit quantitatively stronger social identity effects relative to responders. (3) As redistributive taxes increase, average offers by proposers and the average minimum acceptable offers of responders (both as a proportion of income) decline by almost the same amount, suggesting a shared understanding that is characteristic of social norms. (4) Subjects experience less disadvantageous inequity from ingroup members relative to outgroup members.

Nonlinear pricing under inequity aversion

We consider a monopoly which practices nonlinear pricing, where buyers may have inequity-averse preferences. Each buyer has a valuation for the good, drawn from a distribution. The monopoly knows the distribution but not the realizations. We introduce the possibility that any buyer can be inequity-averse (fair types) or not (neutral types), in addition to different demand types. Fair types get a disutility from inequity captured through a utility function in the spirit of the one introduced by Fehr and Schmidt (1999). We characterize the optimal nonlinear pricing and show that the degree of suboptimality increases, and the monopoly profit decreases, as the degree of the inequity aversion increases. We also show that some or all of the neutral types with low demand are strictly better off, when there are inequity-averse types in the environment.

Peer effects and risk sharing in experimental asset markets

We investigate the effect of introducing information about peer portfolios in an experimental Arrow–Debreu economy. Confirming the prediction of a general equilibrium model with inequality averse preferences, we find that peer information leads to reduced variation in payoffs within peer groups. Information also improves risk sharing, as the data suggests that experiencing earnings deviations from peers induces a shift to more balanced portfolios. In a treatment where we highlight the highest earner, we observe a reduction in risk sharing, while highlighting the lowest earner has no effects compared to providing neutral information. Our results indicate that the presence of social information and its framing is an important determinant of equilibrium in financial markets.

Identity and Redistribution: Theory and Evidence.

We contribute to a growing literature on redistribution and identity. We propose a theoretical model that embeds social identity concerns, as in Akerlof and Kranton (2000), with inequity averse preferences, as in Fehr and Schmidt (1999). We conduct an artefactual ultimatum game experiment with registered members of British political parties for whom both identity and redistribution are salient. The empirical results are as follows. (1) Proposers and responders demonstrate ingroup-favoritism. (2) Proposers exhibit quantitatively stronger social identity effects relative to responders. (3) As redistributive taxes increase, offers by proposers and the minimum acceptable offers of responders (both as a proportion of income) decline by almost the same amount, suggesting a shared understanding that is characteristic of social norms. (4) Subjects experience more disadvantageous inequity from outgroup members relative to ingroup members.

Revealed Social Preferences

We use a revealed preference approach to develop tests for the observed behavior to be consistent with theories of social preferences. In particular, we provide nonparametric criteria for the observed set of choices to be generated by inequality averse preferences and increasing benevolence preferences. These tests can be applied to games commonly used to study social preferences: dictator, ultimatum, investment (trust) and carrot-stick games. We further apply these tests to experimental data on dictator and ultimatum games. Finally, we show how to identify the levels of altruism and fair outcomes using the developed revealed preference conditions.

Voting for the distribution rule in a Public Good Game with heterogeneous endowments

This paper analyzes the impact of inequality in the distribution of endowments on cooperation. We conduct a lab experiment using a dynamic Public Good Game to test this relation. We introduce the possibility of choosing among three different redistribution rules: Equidistribution, Proportional to contribution and Progressive to endowment. This novelty in a dynamic environment allows us to analyze how the inequality within groups changes according to individual choices and to investigate if players show inequity averse preferences. Results show that inequality has a negative impact on individual contribution. Players act in order to reduce the initial exogenous inequality. Indeed, in the Treatment with the highest level of inequality, agents vote for reducing the endowment heterogeneity. Moreover, individual contribution is strongly influenced by others’ contributions.

The effect of power imbalances on incentives to make non-contractible investments

We use an experiment to study the effect of ex-post sharing rules on relationship-specific investments in an incomplete contracting context. We find that no power structure can induce first-best investments and that equally productive partners reach more efficient outcomes with a balanced power structure (i.e., equal sharing of returns) than with an asymmetric one. In addition, we find evidence for behavioural effects: partners make higher investments and reach higher efficiency levels than own-payoff maximisation would suggest. This behaviour is in line with a model where decision-makers care about social efficiency. It is not consistent with inequity-averse preferences.

How exposure to markets can favor inequity-averse preferences

This paper shows how market exposure can support the evolution of non-individualistic preferences. In a group, one agent is randomly selected to divide an exogenous endowment. Endowment shares are used for either consumption or market exchange with external merchants. As a more equal endowment distribution attenuates the scope of merchants’ price discrimination, we argue that inequity-averse preferences may lead to a higher utility of consumption and so survive evolutionary pressures. This effect arises from an opportunity to create and extract information rents. We offer a new explanation to the empirical finding that a society's exposure to markets has a positive effect on its members’ sociality.

The Strategic Advantage of Inequality Averse Preferences

It is usually assumed that the sole purpose of agents is to maximize their own material payoff independently from what other agents receive, and that this yields a strategic advantage in terms of receiving a higher payoff compared to other types of players, if any. On the contrary, it is shown that in certain subclasses of games, players with negatively interdependent preferences have an unambiguous strategic advantage over the independent players (Kockesen et al., 2000). We analyze a different type of interdependency in games; in particular, we analyze games where players with inequality averse preferences have a strategic advantage over the independent players.

Are dictators averse to inequality?

We present the results of an experiment designed to identify more clearly the motivation underlying dictators’ behavior. In the typical dictator game, recipients are given no endowment. We give an endowment to the recipient as well as the dictator. This new dimension allows us to test directly for inequality aversion. Our results confirm that the inequality between dictator's and recipient's endowment is a key determinant of the dictator's giving. As we increase the recipient's endowment from 0 to an amount equal to the dictator's endowment, the mean amount passed drops from 30 percent to less than 12 percent of the dictator's endowment, and the proportion of dictators who pass positive amounts falls from 75 percent to 26 percent. Thus the majority of dictators exhibit behavior consistent with inequality averse preferences. On the other hand, only 24 percent of dictators split payoffs equally suggesting that maximin preferences are less important drivers of dictators’ giving.

The role of role uncertainty in modified dictator games

We compare behavior in modified dictator games with and without role uncertainty. Subjects choose between a selfish action, a costly surplus creating action (altruistic behavior) and a costly surplus destroying action (spiteful behavior). While costly surplus creating actions are the most frequent under role uncertainty (64%), selfish actions become the most frequent without role uncertainty (69%). Also, the frequency of surplus destroying choices is negligible with role uncertainty (1%) but not so without it (11%). A classification of subjects into four different types of interdependent preferences (Selfish, Social Welfare maximizing, Inequity Averse and Competitive) shows that the use of role uncertainty overestimates the prevalence of Social Welfare maximizing preferences in the subject population (from 74% with role uncertainty to 21% without it) and underestimates Selfish and Inequity Averse preferences. An additional treatment, in which subjects undertake an understanding test before participating in the experiment with role uncertainty, shows that the vast majority of subjects (93%) correctly understand the payoff mechanism with role uncertainty, but yet surplus creating actions were most frequent. Our results warn against the use of role uncertainty in experiments that aim to measure the prevalence of interdependent preferences.

How Exposure to Markets Can Favor Inequity-Averse Preferences

This paper shows how non-individualistic preferences can be individual fitness maximizing in market-integrated societies. In the model, individuals share an endowment, which is used for consumption and/or purchase of goods on the external market. We show that inequity aversion about endowment distribution can be an optimal response to merchants' price discrimination. Then, assuming that increased consumption means increased individual fitness, we argue that evolutionary selection can favor inequity-averse preferences. We also argue that our model can explain an empirical finding of Henrich et al. (2004) about the positive effect of a society's exposure to markets on its members' sociality.

The Role of Role Uncertainty in Modified Dictator Games

We compare behavior in modified dictator games with and without role uncertainty. Subjects choose between a selfish action, a costly surplus creating action (altruistic behavior) and a costly surplus destroying action (spiteful behavior). While costly surplus creating actions are most frequent under role uncertainty (64%), selfish actions become most frequent without role uncertainty (69%). Also, the frequency of surplus destroying choices is negligible with role uncertainty (1%) but not so without it (11%). A classification of subjects into four different types of interdependent preferences (Selfish, Social Welfare maximizing, Inequity Averse and Competitive) shows that the use of role uncertainty overestimates the prevalence of Social Welfare maximizing preferences in the subject population (from 74% with role uncertainty to 21% without it) and underestimates Selfish and Inequity Averse preferences. Our results warn against the use of role uncertainty in experiments that aim to measure the prevalence of interdependent preferences.

Inequality aversion and diminishing sensitivity

We define inequality aversion as a decision-maker disliking it when his opponents’ payoffs differ from his own, diminishing sensitivity as this effect increasing less-than-proportionately as the opponents’ payoffs move further from the decision-maker’s, and a preference for Robin Hood redistributions as a preference for taking money from a high-payoff opponent and giving it to a low-payoff opponent. Existing models of inequality averse preferences are unable to accommodate all three properties. The three are not inherently inconsistent, though, and we construct a new model which exhibits all three properties.

Discussion of “The Effect of Sunk Costs on the Outcome of Alternating-Offers Bargaining Between Inequity-Averse Agents”

In his article, Ewerhart argues that agents with inequity-averse preferences may overcome the hold-up problem. In this discussion, I focus on the underlying assumptions that he makes and point to some limitations of the model.