Income Heterogeneity in the Voluntary Provision of Dynamic Public Goods

This paper explores the effect of income inequality on the voluntary contributions to a dynamic public good. We find that income heterogeneity has a significant impact both on contributions and welfare. The results show that the often observed decay of cooperation does not carry over to the asymmetric environment considered in this study. Our results also suggest that subjects in each income class make different contribution amounts in an absolute sense and give the same percentage of their income. Moreover, we find that contributions of individuals with the same endowment are sensitive to how heterogeneous the environment is.     

Existence and efficiency of equilibrium in infinite economies with finite aggregate wealth

Summary. We prove the existence and efficiency of equilibrium in economies with infinitely many consumers in which there are finitely many agents who own a positive portion of the aggregate endowment. We prove existence for commodity spaces which are employed in the general equilibrium asset pricing models and use incomplete and intransitive preferences. We discuss the importance of existence of finitely many agents who own a positive portion of the aggregate endowment in obtaining efficient equilibrium. For general equilibrium asset pricing applications we require forward properness only at individually rational Pareto optimal allocations. We provide an Arrow-Debreu model for these economies. We also give an application of our approach and results by employing Stochastic Differential Utility as the utility of each consumer in an infinite horizon model.     

Endogenous timing and income inequality in the voluntary provision of public goods: Theory and experiment

This study theoretically and experimentally investigates the effects of income inequality on donors' decisions regarding timing choices and contributions to public goods when contribution timing is endogenously chosen by contributors. To this end, we use the conventional voluntary provision models of Warr (1983) and Bergstrom, Blume and Varian (1986), with Cobb–Douglas preferences augmented with a two-stage game of Hamilton and Slutsky (1990). The following results were obtained and experimentally confirmed. First, when the distribution of income is extremely unequal, donors are indifferent between the simultaneous and sequential moves in the contribution game. Second, as income inequality is decreased, the simultaneous-move contribution game is likely to emerge because every donor prefers to act as a leader. Nevertheless, a higher-income donor may also prefer to act as a follower without specific social preferences and uncertainty regarding the quality of public goods. Third, most theoretical predictions regarding timing decisions are supported in our laboratory experiment, provided that the participants had enough time to learn the consequences of their timing choices.     

Contribution to a public good under subjective uncertainty

This paper examines how voluntary contributions to a public good are affected by the contributors' heterogeneity in beliefs about the uncertain impact of their contributions. It assumes that contributors have Savagian preferences that are represented by a two‐state‐dependent expected utility function and different beliefs about the benefit that will result from the sum of their contributions. We establish general comparative statics results regarding the effect of specific changes in the distribution of beliefs on the (unique) Nash equilibrium provision of the public good, under certain conditions imposed on the preferences. We specifically show that the equilibrium public good provision is increasing with respect to both first‐ and second‐order stochastic dominance changes in the distribution of beliefs. Hence, increasing the contributors' optimism about the uncertain benefit of their contributions increases aggregate public good provision, as does any homogenization of these beliefs around their mean.     

Dissertation abstract: Contribution to a public good - Theoretical analysis and experimental evidence

The work undertook is located between Public Economic Theory and Experimental Economics. The object of the thesis consists in analysing the aggregate behavior and the individual heterogeneity in a voluntary contribution game. The thesis defended here is that overcontribution in comparison to the Nash equilibrium of the game, can not be explained neither by judgement errors, nor by the information on the individual behaviour of the members in a one given group. The level of contribution observed remains nevertheless inferior to the one simulated using the E.W.A. learning model. The dissertation is composed of three parts and six chapters. The first chapter expresses the various theoretical mechanisms of production of a public good, while the second one presents an overview of the experimental literature using voluntary contribution mechanisms. The second part carries on the introduction of an interior solution in a public good game in order to distinguish an explanation of overcontribution in terms of mistakes or strategies. While chapter three presents the most important works in literature that use an interior solution, the fourth chapter constitutes a personal contribution consisting in an experiment with an interior optimum. Our main result is that individuals contribute a constant part of their social optimum and that overcontribution is not explained by error. We test then the simple learning model R.L. using the observed data on the aggregate level. This model predicts well the observed behaviour. The third part is composed of two experiments where the environment of players is modified. We introduce in chapter five promises as cheap talk and find that they increase contributions at the aggregate level. In chapter six, various conditions of information on individual contributions are tested. The parameter tested is the level of information on “neighbours” contributions given to players. One of the treatments presents full information about individual contributions of the members of the group, while this information is incomplete in the other treatments. Our results show that information has no effect on the level of contribution. We simulate then the EWA learning model both at the aggregate and the individual levels and compare the simulated data to the experimental one. These simulations predict a level of contribution that is higher that the one observed in the experiment. JEL Classification C91, C92, H41 Dissertation Committee: Alan Kirman (Ph.D. Advisor), Université d’Aix-Marseille III Marie-Claire Villeval (Chair), GATE, Lyon, France Jordi Brandts, Universitat Autonoma Barcelona, Spain Charles Noussair, Emory University, Alanta, GA, U.S.A. Sylvie Thoron, GREQAM & Université du Var, France Marc Willinger, Université de Montpellier I, France     

Beliefs and Public Good Provision with Anonymous Contributors

We analyze a static game of public good contributions where finitely many anonymous players have heterogeneous preferences about the public good and heterogeneous beliefs about the distribution of preferences. In the unique symmetric equilibrium, the only individuals who make positive contributions are those who most value the public good and who are also the most pessimistic; that is, according to their beliefs, the proportion of players who most like the public good is smaller than it would be according to any other possible belief. We predict whether the aggregate contribution is larger or smaller than it would be in an analogous game with complete information and heterogeneous preferences, by comparing the beliefs of contributors with the true distribution of preferences. A trade‐off between preferences and beliefs arises if there is no individual who simultaneously has the highest preference type and the most pessimistic belief. In this case, there is a symmetric equilibrium, and multiple symmetric equilibria occur only if there are more than two preference types.     

Efficient allocations under ambiguity

Important implications of the expected utility hypothesis and risk aversion are that if agents have the same probability belief, then consumption plans in every efficient allocation of resources under uncertainty are comonotone with the aggregate endowment, and if their beliefs are concordant, then the consumption plans are measurable with respect to the aggregate endowment. We study these two properties of efficient allocations for models of preferences that exhibit ambiguity aversion using the concept of conditional beliefs, which we introduce in this paper. We provide characterizations of such conditional beliefs for the standard models of preferences used in applications.     

Discrimination via Exclusion: An Experiment on Group Identity and Club Goods

We study using laboratory experiments the impact on cooperation of allowing individuals to invest in group‐specific, excludable public goods. We find that allowing different social groups to voluntarily contribute to such goods increases total contributions. However, a significant proportion of that contribution goes toward the group‐specific club good rather than the public good, even when the latter has higher financial returns to cooperation. We find significant evidence of in‐group biases, which are manifested by positive in‐group reciprocity. That is, club goods allow subjects to display their preferences for interaction with their in‐group members, as well as positive in‐group reciprocity.     

A Field Experiment in Charitable Contribution: The Impact of Social Information on the Voluntary Provision of Public Goods

We study the effect of social information on the voluntary provision of public goods. Competing theories predict that others' contributions might be either substitutes or complements to one's own. We demonstrate a positive social information effect on individual contributions, supporting theories of complementarities. We find the most influential level of social information is drawn from the 90th to 95th percentile of previous contributions. We furthermore find the effect to be significant for new members but not for renewing members. In the most effective condition, social information increases contributions by 12% ($13). These increased contributions do not crowd out future contributions.     

Bergstrom,Blume, and Varian: Voluntary contributions and neutrality

Bergstrom, Blume, and Varian provided a neutrality result for the private provision of public goods that has inspired a considerable literature. The result has significant implications for income redistribution and broader policy interventions. This paper reviews the basic result and its applications, and discusses extensions to general private provision economies.     

Impact of peer comparisons and firm heterogeneity on nonpoint source water pollution: An experimental study

Greg Poe was a pioneer in using experimental economics to test theories and potential policies for controlling ambient pollution. His foundational work showed that, in some settings, policies could induce groups to reduce their nonpoint source (NPS) pollution to socially-efficient levels. Poe’s earlier studies assumed firms were homogeneous, which laid the groundwork for subsequent research to investigate the effect of firm heterogeneity on policy outcomes. We build on the research foundation laid by Poe and his colleagues by using an economic experiment to test the effects of four types of firm heterogeneity and three social norm information treatments on the performance of an ambient tax/subsidy policy. Our experimental results show that heterogeneity reduces the effectiveness of the ambient tax/subsidy policy, but that information nudges can improve outcomes even when there is considerable heterogeneity in the policy environment. Participants were also better able to find and retain their dominant strategies when they were provided with information about similar firms, suggesting that individually-targeted information is more effective than information about aggregate group-level decisions.     

ICT,BUSINESS SERVICES AND LABOUR PRODUCTIVITY GROWTH

This paper focuses on the diffusion of knowledge intensive business services (KIBS) in relation to information and communication technology-based innovations and their effect on productivity growth. Intermediate purchases of KIBS by any other industry determine the extent of KIBS diffusion. This diffusion is seen as part of the broader process of organisational innovations. We find a significant positive relation between this measure of KIBS diffusion and the intensity of information technology (IT). Not only do use of IT and KIBS both contribute positively to labour productivity growth, we also find that the combination of these two inputs adds further to productivity growth for the aggregate economy.     

Conjectural Variations and Voluntary Public Good Provision in a Repeated Game Setting

The purpose of this paper is to show how conjectural variations can be derived as a reduced form in an infinitely repeated game of private provision of public goods. We obtain explicit closed forms of conjectural variations associated with maximal sustainable equilibria in which the sum of the utilities of all of a community's members is maximized for both quadratic and Cobb–Douglas preferences, provided that the resulting sequence of contributions can be sustained as a Nash (or subgame perfect) equilibrium in the underlying repeated game. We also show that positive conjectural variations will emerge as long as people place positive weight on the future, and that those conjectures are positively related to the discount factor.     

Foreign direct investment as a signal

This paper models oligopolistic competition among potential multinational firms in an environment of firm heterogeneity, incomplete information on costs, and strategic interactions. We show that foreign direct investment is more likely if it can serve as a signal of productivity in an environment of incomplete information as firms would like to avoid sending a low productivity signal. Our model shows that this effect is strong enough such that foreign direct investment can be an optimal foreign entry mode even if trade costs are zero.     

Do rational demand functions differ from irrational ones? Evidence from an induced budget experiment

Various studies (e.g. Becker, 1962; Ariely et al., 2003) have noted anomalies concerning the relationship between observed demand and the preferences presumed to motivate it. We re-examine these findings using experimental choice data. After separating our subjects’ choices into rational and irrational subsets based on consistency with the axioms of revealed preference, we estimate and compare demand coefficients. Mirroring Ariely et al.'s ‘coherently arbitrary’ choice, both rational and irrational demand estimates exhibit negative price and positive endowment coefficients. However, a comparison of the full set of demand coefficients indicates significant differences between the two, yielding an observable artefact of the preference hypothesis. Relaxing the goodness-of-fit of the revealed preference test (Afriat, 1987; Varian, 1994) does not alter our findings.     

Data uncertainty and the role of money as an information variable for monetary policy

In this study, we perform a quantitative assessment of the role of money as an indicator variable for monetary policy in the euro area. We document the magnitude of revisions to euro area-wide data on output, prices, and money, and find that monetary aggregates have a potentially significant role in providing information about current real output. We then proceed to analyze the information content of money in a forward-looking model in which monetary policy is optimally determined subject to incomplete information about the true state of the economy. We show that monetary aggregates may have substantial information content in an environment with high variability of output measurement errors, low variability of money demand shocks, and a strong contemporaneous linkage between money demand and real output. As a practical matter, however, we conclude that money has fairly limited information content as an indicator of contemporaneous aggregate demand in the euro area.     

Stochastic equilibria with incomplete financial markets

We demonstrate the existence of equilibria with incomplete financial markets for stochastic economies whose information structure is given by an event tree, restricting attention to purely financial securities, those paying in units of account (e.g., “dollars”). Financial markets may be incomplete: some consumption streams may be impossible to obtain by any trading strategy. Securities may be individually precluded from trade at arbitrary states and dates. Sufficient conditions for the existence of stochastic equilibria are: continuous, convex, strictly monotonic preferences and strictly positive aggregate endowments. These conditions are weakened. A corollary states that any regime of security prices precluding arbitrage can be embedded in an equilibrium.     

On the performance of rule-based contribution schemes under endowment heterogeneity

We experimentally test different rule-based contribution mechanisms in a repeated 4-player public goods game with endowment heterogeneity and compare them to a VCM, distinguishing between a random and an effort-based allocation of endowments. We find that endowment heterogeneities limit the efficiency gains from these rule-based contribution schemes under random allocation. Under effort-based allocations, substantial efficiency gains relative to a VCM occur. These are largely driven by significant reductions of contributions in VCM, while the rule-based mechanisms generate stable efficiency levels, even though falling short in realizing the maximal efficiency gains. Our results indicate that the procedure of endowment allocation impacts the perception of what constitutes a fair burden sharing.     

Evolutionarily stable conjectures and other regarding preferences in duopoly games

We study the evolutionary selection of conjectures in duopoly games when players have other regarding preferences, i.e. preferences over payoff distributions. In both the Cournot and Bertrand duopoly games, the consistent conjectures are independent of other regarding preferences. Both duopoly games have evolutionarily stable conjectures that depend on other regarding preferences but that do not coincide with the consistent conjectures. For increasingly spiteful preferences, the evolutionarily stable conjectures implicate low quantities in the Cournot game and high prices in the Bertrand game, whereas the inverse relationships hold for the consistent conjectures. We discuss our findings in the context of ultimate and proximate causation.     

On the Private Provision of Two or More Public Goods

We extend the simple model of voluntary public good provision to allow for two or more public goods, and explore the new possibilities that arise in this setting. We show that, when there are many public goods, voluntary contribution equilibrium typically generates, not only too low a level of public good provision, but also the wrong mix of public goods. We also analyze the neutrality property in the more general setting, and extend a neutrality proposition of Bergstrom, Blume, and Varian (1986) .