Participation constraints of matching mechanisms

Matching mechanisms have been proposed to improve public good provision in voluntary contributions. However, such decentralized subsidizing mechanisms may not be Pareto‐improving and may suffer from incomplete information and incredible commitment. This paper examines participation constraints of matching mechanisms with small matching rates in two cases of equilibria. At interior equilibria, there always exist small Pareto‐improving matching schemes regardless of preferences. This universal existence is useful for cooperation among heterogeneous players in the context without global information of preferences or at the international level without central governments. At corner equilibria, matching schemes work in different ways and have distinct welfare effects in certain cases, and the existence of Pareto‐improving matching schemes is not universal but is possible under certain conditions. The paper further characterizes Pareto‐improving matching schemes, and shows that it is easier to reach Pareto‐improving matching outcomes if players value more on public goods and have stronger substitution between private and public goods.     

Financing Public Goods by Means of Lotteries

When viewed as taxes, lotteries are routinely criticized as being both inequitable and inefficient. But is this an entirely fair comparison? Frequently lotteries are used in lieu of voluntary contributions by private charities and governments when taxes are not feasible. When heterogeneous individuals with quasi-linear preferences participate in lotteries whose proceeds will be used to fund a public good, we find that, relative to voluntary contributions, wagers in the unique lottery equilibrium (a) increase the provision of the public good, (b) are welfare improving, and (c) provide levels of the public good close to first-best as the lottery prize increases.     

Weak Moral Motivation Leads to the Decline of Voluntary Contributions

We develop a model that accounts for the decay of the average contribution observed in experiments on voluntary contributions to a public good. The novel idea is that people's moral motivation is “weak.” Their judgment about the right contribution depends on observed contributions by group members and on an intrinsic “moral ideal.” We show that the assumption of weakly morally motivated agents leads to the decline of the average contribution over time. The model is compatible with persistence of overcontributions, variability of contributions (across and within individuals), the “restart effect” and the observation that the decay in contributions is slower in longer games. Furthermore, it offers a rationale for conditional cooperation.     

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.     

The Evolutionary Stability of Moral Objections to Free Riding

In this study we explore the endogenous determination of moral objections to free riding. We first derive the individually rational behavior for given preferences. The motivational structure is allowed to evolve evolutionarily based on the comparison of the relative reproductive success of all possible preference types. The tastes that emerge are not necessarily those assumed in models resorting to altruism or moral obligations. In general, an effective social conscience preventing free riding need not be evolutionarily stable. In the first model that we explore, moral objections to free riding and, in turn, voluntary contributions to the provision of public goods are not to be expected with one notable exception, namely unanimity games. In the second model that we explore, the evolutionarily stable probability that an individual develops social conscience is positive.     

‘Us’ and ‘Them’: the origin of identity,and its economic implications

Abstract We investigate the origins of identity and the innate proclivity to draw a distinction between ‘insiders’ and ‘outsiders’. We propose an evolutionary explanation: we argue that identity arises because it facilitates survival. In an evolutionary setting we endogenize preferences and demonstrate that the evolutionarily stable preferences fashioned by natural selection would distinguish between insiders and outsiders. We then work out the implications of such preferences in two contemporary scenarios, one entailing rent‐seeking behaviour and the other involving public good provision. Our results are in conformity with empirical evidence.     

Sustaining cooperation in laboratory public goods experiments: a selective survey of the literature

I survey the literature post Ledyard (Handbook of Experimental Economics, ed. by J. Kagel, A. Roth, Chap. 2, Princeton, Princeton University Press, 1995) on three related issues in linear public goods experiments: (1) conditional cooperation; (2) the role of costly monetary punishments in sustaining cooperation and (3) the sustenance of cooperation via means other than such punishments. Many participants in laboratory public goods experiments are “conditional cooperators” whose contributions to the public good are positively correlated with their beliefs about the average group contribution. Conditional cooperators are often able to sustain high contributions to the public good through costly monetary punishment of free-riders but also by other mechanisms such as expressions of disapproval, advice giving and assortative matching.     

Commitment and matching contributions to public goods

We study multi-stage processes of non-cooperative voluntary provision of public goods. In the first stage, one or more players announce contributions that may be conditional on the subsequent contributions of others. In later stages, players choose their own contributions and fulfill any commitments made in the first stage. Equilibrium contributions are characterized under different assumptions about the commitment ability of players, the number of public goods and whether players commit to matching rates or to discrete quantities. We focus on contribution mechanisms that can emerge and be sustainable without a central authority, and that may be particularly relevant for international public goods. Efficient levels of public goods can be achieved under some circumstances, while in others commitment is ineffective.     

Risk perceptions,voluntary contributions and environmental policy

This article studies the effect of uncertainty on agents’ voluntary contributions to environmental quality. There is uncertainty in future environmental quality and we consider a heterogeneity in individuals’ risk perception. In this context, the social optimum can be decentralized by means of tax-financed government subsidies to private provision. We distinguish the case of a government that represents perfectly agents’ preferences from the case of a government with its own risk preferences. In the two cases, we show that neutrality still holds.     

Public Versus Private Provision of Public Goods

It is well known that public goods are underprovided in a static setting with voluntary contributions. Public provision—in a median voter framework with proportional taxation—generally exceeds private provision. This paper compares private and public provision of public goods in a dynamic setting. In a dynamic setting, voluntary donations can result in efficient provision. Also, majority‐rule solutions exist even when taxes are not proportional to income. At low discount factors, public provision tends to exceed private provision. As patience increases, however, private provision may exceed public provision. This occurs because many outcomes with a low level of public good provision—and potentially large targeted transfer payments to particular individuals—become sustainable under public provision. Under private provision, however, large targeted transfers are unsustainable. To finance the public good, private provision tends to result in benefit taxation, and public provision tends to result in progressive taxation.     

Optimal Income Taxation and Public Good Provision with Endogenous Interest Groups

This paper studies public goods provision when agents differ in earning abilities as well as preferences. Heterogeneity in skills makes redistribution desirable and generates an equity-efficiency trade-off. If tax revenues are devoted to a public good, this trade-off is affected in such a way that income transfers are less desirable. High-skilled individuals thus have an incentive to exaggerate their preferences for public goods. Analogously, low-skilled individuals lobby against public good provision. A requirement of collective incentive compatibility eliminates these biases. It implies that income transfers are increased whenever a public good is provided and are decreased otherwise.     

Public Goods Games,Altruism, and Evolution

I analyze the evolution of altruistic preferences in a population where individuals are matched pairwise to play a one‐shot public goods game. I determine the evolutionarily stable degree of altruism, allowing for assortative matching. The stable degree of altruism is strictly smaller than the degree of assortativity. In particular, if matching is completely random, spite is stable, and a positive degree of assortativity is necessary for pure selfishness to be stable. Furthermore, the stable degree of altruism is increasing in the degree of assortativity, and it depends on the specifics of the public goods game.     

PRIVATE PROVISION OF PUBLIC GOODS AND INFORMATION DIFFUSION IN SOCIAL GROUPS

I describe a dynamic model of costly information sharing where private information affecting collective‐value actions is transmitted by social proximity. Individuals make voluntary contributions toward the provision of a pure public good, and information transmission about quality of provision is a necessary condition for collective provision to take place in a stationary equilibrium. I show that unlike in the case of private goods, better informed individuals face positive incentives to incur a cost to share information with their neighbors and that these incentives are stronger and provision of the pure public good greater the smaller are individuals' social neighborhoods.     

Can a raise in your wage make you worse off? A public goods perspective

We show that a seemingly paradoxical result is possible—an increase in one's wage can reduce one's welfare. Such outcome can occur in an economy populated by agents who value a private good bought using labor income and a public good produced by voluntary time contributions. A raise in the wage (in general, opportunity cost of time) makes each agent substitute away from contributing to the public good, failing to internalize the negative externality imposed on others. The result is a decrease in public good provision. Under quite general conditions, the implied cumulative negative effect on agents' welfare can more than offset the positive effect of the wage raise from increased private good consumption and lead to an equilibrium in which all agents are worse off. Our result is particularly relevant for developing economy settings as it holds for relatively low initial wage levels. We discuss the applicability of our findings to a number of important problems in development, such as market integration, cooperation in common pool resource conservation and social capital.     

Finitely Repeated Voluntary Provision of a Public Good

This paper theoretically explores the voluntary provision of a public good when either one of the following holds: (i) agents’ utility is the sum of their monetary earnings and a nonmaterial component, or (ii) agents’ exhibit satisficing behavior. We show that a small degree of either nonmaterial payoffs or satisficing behavior can generate large contributions in a finitely repeated game, even if the incentive to free‐ride on others’ contributions calls for negligible public good provision in the static game. The equilibrium is characterized by a sharp decline in contributions toward the end of the game. Several comparative results regarding group size and technology are consistent with laboratory data obtained in experimental studies. The model also predicts the restart effect observed in previous experiments.     

Global public goods and unilateral matching mechanisms

While conventional agreements on international public goods require bilateral or multilateral cooperation, we show that unilateral action through matching mechanisms with a self‐commitment device can possibly generate Pareto‐improving outcomes. Even without commitment, unilateral matching may also benefit both players at corner situations. We further characterize the conditions under which this desirable outcome is achieved, particularly highlighting the role of the income distribution and its interplay with the preferences. Moreover, we propose a variant of unilateral matching that can generate Pareto‐improving outcomes regardless of the preferences and the income distribution, indicating that income inequality may not be an obstacle for improving public good provision through unilateral matching.     

Matching behavior and collective action: Some experimental evidence

A new approach to explaining voluntary collective action, emphasizing strategic interactions of actors in their contributions to the provision of a public good, is tested experimentally. The results support this approach, and tend to reject the conventional, Cournot theory of the provision of public goods. Among the findings are a positive interaction between individual contributions to the provision of a public good, and a U-shaped time trend in combined contributions.     

Paretian dictators: constraining choice in a voluntary contribution game

We explore individuals’ preferences over limiting the choice sets of others in an environment with externalities. Specifically, we conduct public goods games in which participants can mandate the contributions of others or restrict choices to a subset of feasible contributions levels. We find that, relative to a baseline treatment in which individuals make choices from the set of all contribution alternatives, allowing individuals to constrain the choices of others results in more efficient outcomes. We discuss these results in light of the literature on behavioral theories of reciprocity and conditional cooperation and in regards to the literature on pre-constitutional design, political institutions, and social choice.     

Social network and private provision of public goods

Using a simple model with interdependent utilities, we study how social networks influence individual voluntary contributions to the provision of a public good. Departing from the standard model of public good provision, we assume that an agent’s utility has two terms: (a) ‘ego’-utility derived from the agent’s consumption of public and private goods, and (b) a social utility which is the sum of utility spillovers from other agents with whom the agent has social relationships. We establish conditions for the existence of a unique interior Nash equilibrium and describe the equilibrium in terms of network characteristics. We show that social network always has a positive effect on the provision of the public good. We also find that, in networks with “small world”-like modular structures, ‘bridging’ ties connecting distant parts of social network play an important role inducing an agent’s contribution to public good. Assumptions and results of the model are discussed in relation to the role of social capital in community-level development projects and to the effect of innovation networks on firms’ R&D investments.     

The relevance of private information in mechanism design

Recent results in mechanism design show that as long as agents have correlated private information and are sufficiently risk neutral, it is possible to design mechanisms that leave agents with arbitrarily small information rents. We show that these full-rent-extraction results hinge on the implicit assumption that the agents’ beliefs uniquely determine their preferences. We present an example of the voluntary provision of a public good in which this assumption is relaxed, and consequently, even in highly correlated environments, if agents’ beliefs do not uniquely determine their preferences, then the extraction of the agents’ entire information rents is impossible.