Endogenous Group Formation

While the rules governing the formation of groups engaging in collective action may have significant impact on group size and behavior of members, most experiments on public goods have been conducted with the subjects in exogenously fixed groups or of fixed sizes. We study endogenous formation of groups in a public‐goods provision game by allowing subjects to change groups under three sets of rules: free entry/exit, restricted entry with free exit, and free entry with restricted exit. We find that the rules governing entry and exit do have a significant impact on individual behavior and group‐level outcomes.     

Coalition Stability in Public Goods Provision: Testing an Optimal Allocation Rule

We test the canonical model of international environmental agreements (IEAs) in a laboratory setting with asymmetric agents. IEA participation represents coalition formation and public good provision where there are gains to cooperation, but an incentive to free-ride. We test four competing methods of dividing the coalition’s worth: a recently proposed optimal rule which accounts for subjects’ payoffs as a single free-rider, the Shapley value, the Nash bargaining solution, and an equal split. Each treatment generates the theoretically predicted coalition size more often than not. The shares of the potential gains to cooperation achieved by each rule are: 51, 36, 40 and 13%, respectively. These results highlight the importance of using an optimal rule to improve IEAs, and more broadly for voluntary public good provision.     

Group size and the (in)efficiency of pure public good provision

Are larger groups better at cooperation than smaller groups? This paper investigates, under controlled conditions, the presence and direction of a possible group size effect in pure public good provision by large heterogeneous groups. Employing subjects drawn from the general population and introducing Internet-based procedures to study this question, we collected experimental evidence from 1110 subjects playing a linear public goods game in groups of 10, 40, and 100 members. We find a positive and significant group size effect: Increasing group size by a factor of 10 (4) increased efficiency by 10 (6) percent. The effect arose at the intensive margin and with repetition. Those who contributed contributed more in larger groups. Larger and smaller groups had similar initial contribution levels, but cooperation rates declined more slowly in the larger groups. Free-riding was invariant to group size, despite subjects׳ persistent beliefs of a negative group size effect at the extensive margin. Further econometric examination of the data supports these findings and provides starting points for future theoretical and experimental research on the group size effect.     

The Role of Market Size in the Formation of Jurisdictions

Administrative and political reorganization is being actively debated even in the mature, stable economies of Western Europe. This paper investigates the possibility that such a reorganization is tied to the integration of economic markets. The paper describes a model where heterogeneous individuals form coalitions for the provision of a public good and shows that the number and composition of these jurisdictions depend on the overall size of the market. The range of economic activities engaged in by jurisdiction members increases when the size of the market increases, and so does the range of their preferences over the public good. The result is a change in the endogenous borders of the jurisdictions, and a reorganization of all coalitions. The optimal number of jurisdictions is unique and increases with market size. In the absence of compensating transfers, however, the decentralized equilibrium need not be optimal and is not unique, although     

Optimal Nonlinear Redistributive Taxation and Public Good Provision in an Economy with Veblen Effects

This paper deals with the consequences of the assumption of negatively interdependent preferences for the shape of the optimal nonlinear income tax and the efficient level of public good provision in a setting where the agents' market ability is private information. The analysis points out that the terms added in the tax formulas due to the presence of Veblen effects might justify a reduction in the optimal marginal tax rates faced by the different individuals. Also, the desirability of negative marginal tax rates cannot be ruled out. With respect to the issue of the optimal level of public good provision, I derive a modified Samuelson rule and highlight the fact that the Veblen‐based part of the formula might require to distort downwards the efficient level of public good provision.     

Non-monotonic group-size effect in repeated provision of public goods

This paper analyzes the effect of a change in group size on incentives to contribute in repeated provision of pure public goods. We develop a model in which group members interact repeatedly, and might be temporarily unable to contribute to public goods production during some periods. We show that an increase in the group size generates two opposite effects – the standard free-riding effect that suppresses cooperation, and the novel large-scale effect that enhances cooperation. Our results indicate that the former effect dominates in relatively large groups while the latter dominates in relatively small groups. We, therefore, provide a rationale for a non-monotonic group-size effect that may explain previous empirical and experimental findings.     

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.     

On the evolution of conditional cooperation

A long series of laboratory and field experiments, as well as conventional empirical studies, has established that (1) individuals voluntarily provide themselves with public goods at levels exceeding those predicted by the Nash voluntary contributions mechanism, and (2) agents reciprocate increases in the contributions of their counterparts in such settings (conditional cooperation). This paper presents a simple model of the evolution of preferences for conditional cooperation in the presence of a public good, which explains these two empirical findings without employing reputational or group selection arguments. In this model, individuals inherit preferences to match other agents' contributions to the provision of a public good, at some specified “matching rate.” Agents whose preferences induce them to be relatively successful – in material terms – increase in number, from one generation to the next. Under complete information and with randomly matched groups of N agents who have quasilinear preferences over the public good and a private good, the unique evolutionarily stable matching rate is 1, leading to Pareto optimal voluntary provision of the public good, regardless of group size N. The evolutionarily stable matching rate can be viewed as an endogenous social norm.     

Exchange Rules and the Incentive Compatibility of Choice Experiments

The incentive properties of stated-preference surveys continue to be a central debate in the valuation of public goods. The majority of empirical studies have focused on incentive properties of contingent valuation questions in relation to situations where answers have monetary consequences. This research explores the incentive properties of repeated, attribute-based choice questions when subjects are provided with an explicit connection between choices and outcomes. Two market/provision-rules are investigated: a posted-price market and a plurality-rule vote. These two provision rules are contrasted to treatments in which no provision rule is discussed—subjects are simply asked to choose their preferred alternative. These three hypothetical choice treatments are compared with a binding choice treatment. While none of the public good treatments are theoretically incentive compatible, we include a comparison of hypothetical and binding choices for a private-good that is incentive compatible. The private good experiments indicate that marginal willingness to pay (WTP) estimates from the hypothetical treatment are larger, but not statistically different than corresponding estimates in the binding choice treatment. Results for the public good experiments indicate that marginal WTP estimates from the hypothetical treatments are much larger, and statistically different than corresponding estimates in the binding choice treatment. The bias is largest when no provision rule is discussed. The bias is reduced with the inclusion of a provision rule, but surprisingly, there was no difference across provision rule treatments. Overall, our results indicate that choice experiments involving a public good should include a provision rule to reduce bias, but the resulting marginal WTP estimates may still be more biased, on average, than those arising from contingent valuation survey formats.     

PUBLIC GOOD PROVISION WITH CONSTITUTIONAL CONSTRAINT

This article studies the public good provision problem, in which the principal faces a constitutional constraint in the sense that in order for a public good provision mechanism to be implemented, it must first be approved by agents under a prespecified voting rule. I find that as long as the voting rule is not the unanimity rule, the principal can propose a mechanism such that first‐best efficiency of provision of the public good is achieved. I also consider various constraints, such as prohibition of discriminatory mechanisms and the existence of vote buying, and discuss optimal voting rules in these situations.     

On the Frequency of Interior Cournot–Nash Equilibria in a Public Good Economy

In a public good economy the distribution of initial income is an important determinant of how many individuals contribute to the public good in Cournot–Nash equilibrium. In this paper, first a simple formula is derived that provides a measure for the size of the set of income distributions leading to an interior Cournot–Nash equilibrium in which all individuals contribute to the public good. Furthermore, we give an estimate for the frequency that all members of a certain subgroup of the population are contributors.     

Free Riding on Altruism and Group Size

It is shown that altruism does not affect the equilibrium provision of public goods although altruism takes the form of unconditional commitment to contribute. The reason is that altruistic contributions completely crowd out selfish voluntary contributions. That is, egoists free ride on altruism. It is also shown that public goods are less likely to be provided in larger groups. The only qualification to our results is when the probability of altruism is so high that it is a dominant strategy for all egoistic players to free ride. In this case, actually, both altruism and the larger group facilitate public good provision.     

Optimal Fiscal Policies,Congestion and Over‐entry*

By shedding light on market imperfections and the congestion of public goods, we show that free entry in a market equilibrium will lead to excessive entry relative to the social optimum. Moreover, by specifying a generalized congestion function, it is also shown that different fiscal policies, including labor income tax, capital income tax and government expenditure, play a distinct role in terms of remedying market distortions. Specifically, optimal income taxes decrease with the degree of market imperfections in order to remove the monopoly inefficiency, while they increase with the degree of congestion in order to remedy the adverse externality caused by congestion distortion. Since a higher degree of increasing returns to an expansion in the variety of intermediate goods is found to intensify the congestion effect of government infrastructure expenditure, the optimal rule of government expenditure proposed by Barro (1990) should be modified.     

Membership in citizen groups

We analyze the coordination problem of agents deciding to join a group that uses membership revenues to provide a discrete public good and excludable benefits. The public good and the benefits are jointly produced, so that benefits are valued only if the group succeeds in providing the public good. With asymmetric information about the cost of provision, the static membership game admits a unique equilibrium and we characterize the optimal membership fee. We show that heterogeneity in valuations for the excludable benefits is always detrimental to the group. However, in a dynamic contest in which heterogeneity arises endogenously (returning members receive additional seniority benefits at the expense of junior members), we show that, in the ex-ante optimal contract, offering seniority benefits is beneficial for the group, despite the heterogeneity in valuations created.     

Birth,death and public good provision

We explore the effect of fixed versus dynamic group membership on public good provision. In a novel experimental design, we modify the traditional voluntary contribution mechanism (VCM) by periodically replacing old members of a group with new members over time. Under this dynamic, overlapping generations matching protocol we find that average contributions experience significantly less decay over time relative to a traditional VCM environment with fixed group membership and a common termination date. These findings suggest that the traditional pattern of contribution and decay seen in many public goods experiments may not accurately reflect behavior in groups with changing membership, as is the case in many real-world environments.     

Lotteries, Group Size, and Public Good Provision

We analyze the effect of group size on public good provision under the Morgan (2000) lottery mechanism. For a pure public good, the lottery performs quite well as public good provision is found to increase in group size, even when the lottery prize is held constant. By contrast, for fully rival public goods, per capita provision is found to decrease in group size, even when the lottery prize is proportional to group size. Further, the per capita level of provision will approach zero when group size is sufficiently large.     

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.     

Non‐Governmental Public Norm Enforcement in Large Societies as a Two‐Stage Game of Voluntary Public Good Provision

In small groups, norm enforcement is achieved through mutual punishment and reward. In large societies, norms are enforced by specialists such as government officials. However, not every public cause is overseen by states, for instance those organized at the international level. This paper shows how nongovernmental norm enforcement can emerge as a decentralized equilibrium. As a first stage, individuals voluntarily contribute to a nongovernmental agency that produces an incentive system. The second stage is the provision of a public good on the basis of private contributions. The incentive system increases contributions by means of public approval or disapproval of behavior. It is shown that, even in large populations, nongovernmental norm enforcement can be supported in a noncooperative equilibrium of utility‐maximizing individuals. This result is in sharp contrast to those obtained in the standard situation of voluntary provision of an intrinsic public good which—without altruism or related motives—is eroded by free‐riding. Reliance on altruistic behavior is not required in supplying the second‐order public good “norm enforcement” in large societies.     

Public good provision with optimal and non-optimal commodity taxation: The single-consumer case

The criterion for welfare-enhancing changes in the level of public good provision is studied in a model with optimal, and more general, commodity tax structures. The welfare rule is sensitive to the precise nature of interactions between public spending and (ordinary or compensated) demands for taxed goods.     

Optimal democratic mechanisms for taxation and public good provision

We study the interdependence of optimal tax and expenditure policies. An optimal policy requires that information on preferences is made available. We first study this problem from a general mechanism design perspective and show that efficiency is possible only if the individuals who decide on public good provision face an own incentive scheme that differs from the tax system. We then study democratic mechanisms with the property that tax payers vote over public goods. Under such a mechanism, efficiency cannot be reached and welfare from public good provision declines as the inequality between rich and poor individuals increases.