Giving little by little: Dynamic voluntary contribution games

Charitable contributions are frequently made over time. Donors are free to contribute whenever they wish and as often as they want, and are frequently updated on the level of contributions by others. A dynamic structure enables donors to condition their contribution on that of others, and, as Schelling [Schelling, Thomas C., The Strategy of Conflict Cambridge, MA: Harvard University Press, 1960.] suggested, it may establish trust thereby increasing charitable giving. Marx and Matthews [Marx, Leslie, and Steven Matthews, “A Dynamic Voluntary Contribution to a Public Project,” Review of Economic Studies, 67, 2000, 327-358.] build on Schelling's insight and show that multiple contribution rounds may secure a provision level that cannot be achieved in the static, one-shot setting, but only if there is a discrete, positive payoff jump upon completion of the project. We examine these two hypotheses experimentally using static and dynamic public good games. We find that contributions are indeed higher in the dynamic than in the static game. However, in contrast to the predictions, the increase in contributions in the dynamic game does not depend critically on the existence of a completion benefit jump or on whether players can condition their decisions on the behavior of other members of their group.     

After you—endogenous sequencing in voluntary contribution games

We examine contributions to a public good when some donors do not know the true value of the good. If donors in such an environment determine the sequence of moves, two contribution orders may arise as equilibria. Either the uninformed and informed donors contribute simultaneously or the informed contribute prior to the uninformed. Sequential moves result in a larger provision of the public good, because the follower mimics the action of the leader, and in accounting for this response the leader chooses to contribute when it is efficient to do so. An experimental investigation of the game shows that the donors predominantly choose to contribute sequentially, and that the resulting contributions are larger than those of the simultaneous-move game. Although the gain from sequential moves is smaller when the sequence is set exogenously, our results suggest that the involved parties would benefit from having sequential moves imposed upon them.     

Leading-by-example and signaling in voluntary contribution games: an experimental study

We report experimental results on the effect of leadership in a voluntary contribution game. Consistent with recent theories we find that leading-by-example increases contributions and earnings in an environment where a leader has private information about the returns from contributing (Hermalin in Am Econ Rev 88:1188–1206, 1998; Vesterlund in J Public Econ 87:627–657, 2003). In contrast the ability to lead-by-example has no effect on total contributions and earnings when such returns are commonly known. In our environment the success of leadership therefore appears to be driven by signaling rather than by nonpecuniary factors such as reciprocity. This paper was started while the authors were visiting the Harvard Business School during the fall of 2000. We are grateful for their hospitality and financial support. Vesterlund acknowledges support from the National Science Foundation and Potters from the Royal Netherlands’ Academy of Arts and Sciences. We thank Henrik Orzen for assistance in conducting the experiment. We also thank David Cooper and an anonymous referee who helped us improve the paper. Finally we thank Chris Anderson, Jim Andreoni, John Duffy, Simon Gaechter, Ernan Haruvy, Muriel Niederle, Jack Ochs, Elke Renner, Al Roth, participants at ESA-meetings (Barcelona, 2001), the Leadership and Social Interactions Workshop (Lyon, 2003), SITE (Stanford, 2004) and seminar participants at Alabama, CMU, Duke, Keele, Maryland, Nottingham, NYU, Pittsburgh, OSU, and York for valuable comments.     

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.     

The strategic impact of voluntary vs. mandated vertical restraints and termination restrictions on exclusion of rivals

Journal of Regulatory Economics - It has been shown that manufacturers can employ vertical practices and restraints to prevent entry in markets where upstream entrants require downstream...     

Not just babble: Opening the black box of communication in a voluntary contribution experiment

We let subjects in a voluntary contribution experiment make non-binding numerical announcements about their “possible” contributions and, in some treatments, send written promises to contribute specific amounts. We find that announcements were responded to both by others’ announcements and by real play, for example announcements led to costly punishment when found to be misleading. We also find that adding pre-play announcements to treatments with punishment can increase efficiency by letting cost-free warnings substitute for costly punishment. The threat of punishing false announcements and promises helps reduce false signals, but only when promise statements can be sent is the effect sufficient for achieving greater efficiency.     

Do non-strategic sanctions obey the law of demand? The demand for punishment in the voluntary contribution mechanism

The prospect of receiving a monetary sanction for free riding has been shown to increase contributions to public goods. We ask whether the impulse to punish is unresponsive to the cost to the punisher, or whether, like other preferences, it interacts with prices to generate a conventional demand curve. In a series of experiments, we randomly vary the cost of reducing the earnings of other group members following voluntary contribution decisions. In our design, new groups are formed after each interaction and no subject faces any other more than once, so there is no strategic reason to punish. We nonetheless find significant levels of punishment, and we learn that both price and the extent to which the recipient's contribution is below the group mean are significant determinants of the quantity of punishment demanded. Moreover, punishment is mainly directed at free riders even when it costs nothing to the punisher.     

Entry in contests with incomplete information: Theory and experiments

This paper studies entry decisions in contests with private values. Potential contestants observe their value and the common opportunity cost of entry, and make entry decisions simultaneously. Theory predicts that whether or not contestants are informed of the number of entrants prior to choosing their expenditures has no effect on entry or aggregate expenditures. We test these assertions in our experiments. We find substantial over-entry in both information structures. However, entry is higher when contestants are informed. Since expenditures do not, on average, differ across information structures, aggregate expenditure is also higher when contestants are informed. Contestants earn on average less than the opportunity cost of entry.     

Confusion and learning in the voluntary contributions game

We use a limited information environment to assess the role of confusion in the repeated voluntary contributions game. A comparison with play in a standard version of the game suggests, that the common claim that decision errors due to confused subjects biases estimates of cooperation upwards, is not necessarily correct. Furthermore, we find that simple learning cannot generate the kind of contribution dynamics commonly attributed to the existence of conditional cooperators. We conclude that cooperative behavior and its decay observed in public goods games is not a pure artefact of confusion and learning.     

Urbanization with and without industrialization

We document a strong positive relationship between natural resource exports and urbanization in a sample of 116 developing nations over the period 1960–2010. In countries that are heavily dependent on resource exports, urbanization appears to be concentrated in “consumption cities” where the economies consist primarily of non-tradable services. These contrast with “production cities” that are more dependent on manufacturing in countries that have industrialized. Consumption cities in resource exporters also appear to perform worse along several measures of welfare. We offer a simple model of structural change that can explain the observed patterns of urbanization and the associated differences in city types. We note that although the development literature often assumes that urbanization is synonymous with industrialization, patterns differ markedly across developing countries. We discuss several possible implications for policy.     

Efficiency and group size in the voluntary provision of public goods with threshold preference

What is the optimal group size in the voluntary provision of public goods in a purely altruistic economy? The popular consensus on this fundamental question is that the free-rider problem worsens as the group size increases. This study provides a counterexample of the consensus by featuring plausible threshold preferences for certain typical public goods. Under these preferences, marginal utility hardly diminishes below a threshold level, but declines significantly in close proximity to the threshold and nearly drops to zero above the threshold. We find that threshold preferences significantly reduce inefficiency. We also show that if marginal costs increase, then the threshold preferences lead to a partly positive relationship between efficiency and group size, which allows us to detect the locally efficient group size. Moreover, the locally efficient group size is proportional to the slope of the marginal costs as well as the threshold of marginal utility.     

Do voluntary commitment mechanisms improve welfare? The effect of mandatory and voluntary oaths in a social dilemma

We investigate whether oaths can enforce property rights in a social dilemma and increase welfare. We examine the impact of mandatory and voluntary oaths in a laboratory experiment where individuals can produce wealth, protect accumulated wealth, and take wealth from others. Individuals are more productive when oaths are mandatory compared to a no-oath environment. Subjects’ voluntary signing oaths behave similarly to those who sign a mandatory oath. When the oath is voluntary, nonoath-taking individuals engage in nonproductive behavior, negating the positive impact from the voluntary oath. Our results show that altering commitment mechanisms can result in varying welfare levels.     

Tariffs,quotas, and voluntary export restraints with endogenous labor supply

This paper develops a two-good, small-country, general equilibrium trade model with endogenous labor supply and wage taxes, and where trade is restricted by a tariff, or an import quota, or VERs. Within this framework we derive (i) the employment and welfare effects of the three types of trade restrictions, (ii) the price effect of an import quota and VERs, and (iii) the shadow price of foreign exchange under each type of trade restriction. The present results are compared to those where (i) factor supplies are fixed, and (ii) perfect international capital mobility exists.     

On the potential for observational equivalence in experiments on risky choice when a power value function is assumed

We demonstrate theoretically and illustrate the implications of assuming power utility when the true function is of the expo-power form. Empirical results can appear to be consistent with cumulative prospect theory when they are in fact generated from a Markowitz model.     

Sealed bid auctions with ambiguity: Theory and experiments

This study presents a laboratory experiment of the first and second price sealed bid auctions with independent private values, where the distribution of bidder valuations may be unknown. In our experimental setting, in first price auctions, bids are lower with the presence of ambiguity. This result is consistent with ambiguity loving in a model that allows for different ambiguity attitudes. We also find that the first price auction generates significantly higher revenue than the second price auction with and without ambiguity.     

Coordination and bargaining power in contracting with externalities

Building on Genicot and Ray [G. Genicot, D. Ray, Contracts and externalities: How things fall apart, J. Econ. Theory 131 (2006) 71-100] we develop a model of non-cooperative bargaining that combines the two main approaches in the literature of contracting with externalities: the offer game (in which the principal makes simultaneous offers to the agents) and the bidding game (in which the agents make simultaneous offers to the principal). Allowing for agent coordination, we show that the outcome of our bargaining procedure may differ remarkably from those of the offer and the bidding games. In particular, we find that bargaining can break agents' coordination and that the principal's payoff can be decreasing in his own bargaining power.     

Testing exclusion restrictions and additive separability in sample selection models

Standard sample selection models with non-randomly censored outcomes assume (i) an exclusion restriction (i.e., a variable affecting selection, but not the outcome) and (ii) additive separability of the errors in the selection process. This paper proposes tests for the joint satisfaction of these assumptions by applying the approach of Huber and Mellace (Testing instrument validity for LATE identification based on inequality moment constraints, 2011) (for testing instrument validity under treatment endogeneity) to the sample selection framework. We show that the exclusion restriction and additive separability imply two testable inequality constraints that come from both point identifying and bounding the outcome distribution of the subpopulation that is always selected/observed. We apply the tests to two variables for which the exclusion restriction is frequently invoked in female wage regressions: non-wife/husband’s income and the number of (young) children. Considering eight empirical applications, our results suggest that the identifying assumptions are likely violated for the former variable, but cannot be refuted for the latter on statistical grounds.     

Identity and social exclusion: an experiment with Hispanic immigrants in the U.S.

In this study we conduct a lab-in-the-field experiment with low-income Hispanics in three neighborhoods in a large city in the U.S. to investigate how identity and social exclusion influences individual contributions to fund local public goods. We find that while the strength of identity has a significant and positive impact on individual contributions to local public goods, the perception of social exclusion significantly decreases contributions. Our findings thus suggest factors that may impede full civic participation, and shed important light on potential policies to increase integration of immigrants and ethnic minorities into mainstream society.