Tore Ellingsen

Positive Interactions Promote Public Cooperation

Carrots Are Better Than Sticks The challenge of dealing with freeloaders—who benefit from a common good but refuse to pay their “fair share” of the costs—has often been met in theoretical and laboratory studies by sanctioning costly punishment, in which contributors pay a portion of their benefit so that freeloaders lose theirs. Rand et al. (p. 1272; see the news story by Pennisi and the cover) added a private interaction session after each round of the public goods game during which participants were allowed to reward or punish other members of their group. The outcome showed that reward was as effective as punishment in maintaining a cooperative mindset, and doing so via rewarding interactions allowed the entire group to prosper because less is lost to the costs of punishing. Reward is as good as punishment to promote cooperation, costs less, and increases the share out of resources up for grabs. The public goods game is the classic laboratory paradigm for studying collective action problems. Each participant chooses how much to contribute to a common pool that returns benefits to all participants equally. The ideal outcome occurs if everybody contributes the maximum amount, but the self-interested strategy is not to contribute anything. Most previous studies have found punishment to be more effective than reward for maintaining cooperation in public goods games. The typical design of these studies, however, represses future consequences for today’s actions. In an experimental setting, we compare public goods games followed by punishment, reward, or both in the setting of truly repeated games, in which player identities persist from round to round. We show that reward is as effective as punishment for maintaining public cooperation and leads to higher total earnings. Moreover, when both options are available, reward leads to increased contributions and payoff, whereas punishment has no effect on contributions and leads to lower payoff. We conclude that reward outperforms punishment in repeated public goods games and that human cooperation in such repeated settings is best supported by positive interactions with others.

In-Kind Finance: A Theory of Trade Credit

It is typically less profitable for an opportunistic borrower to divert inputs than to divert cash. Therefore, suppliers may lend more liberally than banks. This simple argument is at the core of our contract theoretic model of trade credit in competitive markets. The model implies that trade credit and bank credit can be either complements or substitutes. Among other things, the model explains why trade credit has short maturity, why trade credit is more prevalent in less developed credit markets, and why accounts payable of large unrated firms are more countercyclical than those of small firms.

Testing Guilt Aversion

Guilt averse individuals experience a utility loss if they believe they let someone down. For example, generosity depends on what the donor believes that the recipient expects to receive. We measure guilt aversion in three separate experiments: a dictator game experiment, a complete information trust game experiment, and a hidden action trust game experiment. In the experiments we inform donors about the beliefs of the matched recipients, while eliciting these beliefs so as to maximize recipient honesty. The correlation between generous behavior and elicited beliefs is close to zero in all three experiments, suggesting that guilt aversion is smaller than previously thought.

A randomized trial of the effect of estrogen and testosterone on economic behavior

Existing correlative evidence suggests that sex hormones may affect economic behavior such as risk taking and reciprocal fairness. To test this hypothesis we conducted a double-blind randomized study. Two-hundred healthy postmenopausal women aged 50–65 years were randomly allocated to 4 weeks of treatment with estrogen, testosterone, or placebo. At the end of the treatment period, the subjects participated in a series of economic experiments that measure altruism, reciprocal fairness, trust, trustworthiness, and risk attitudes. There was no significant effect of estrogen or testosterone on any of the studied behaviors.

Externalities vs internalities: a model of political integration

Decentralized government lead to inter-regional externalities. Whereas an integratedjurisdiction solves the externality problem, centralized government entails other costs - in particular a neglect for minority interests. The paper models formally the trade-off between these two forces in determining the optimum as well as the equilibrium design of jurisdictions. Both the relative size of regions and the distribution of tastes are shown to be important parameters of the problem.

Social framing effects: Preferences or beliefs?

In an otherwise neutrally described Prisonersʼ dilemma experiment, we document that behavior is more likely to be cooperative when the game is called the Community Game than when it is called the Stock Market Game. However, the difference vanishes when only one of the subjects is in control of her action. The social framing effect also vanishes when the game is played sequentially. These findings are inconsistent with the hypothesis that the Community label triggers a desire to cooperate, but consistent with the hypothesis that social frames are coordination devices. More generally, our evidence indicates that social frames enter peopleʼs beliefs rather than their preferences.

Do People Care About Social Context? Framing Effects in Dictator Games

Many previous experiments document that behavior in multi-person settings responds to the name of the game and the labeling of strategies. Usually these studies cannot tell whether frames affect preferences or beliefs. In this Dictator game study, we investigate whether social framing effects are also present when only one of the subjects makes a decision, in which case the frame may only affect preferences. We find that behavior is insensitive to social framing.

Foreign Direct Investment and the Political Economy of Protection

This paper makes the point that an import-competing industry may not want maximal protection. The reason is that a high level of protection encourages inward foreign direct investment, which could be even less desirable than import competition. A government captured by the domestic import-competing industry consequently will set the level of protection low enough to limit direct foreign entry. This paper also establishes results regarding the form of protection. Voluntary export restraints are shown to be the domestic industrys desired means of protection, because leaving export rents with foreigners inhibits foreign direct investment. Copyright 1999 by Economics Department of the University of Pennsylvania and the Osaka University Institute of Social and Economic Research Association.

Monitoring and Pay

The shirking model of efficiency wages has been thought to imply that monitoring and pay are substitute instruments for motivating workers. We demonstrate that this result is not generally true. As monitoring becomes cheaper, a given effort level will be implemented with more monitoring and less pay, but it is typically also optimal to implement a higher effort. The article provides conditions under which the latter “scale effect” dominates the former “substitution effect” and vice versa. If the ease of monitoring varies across occupations, the model predicts a nonmonotonic relationship between the wage level and workers’ rents.

Does Evolution Solve the Hold-up Problem?

The paper examines the theoretical foundations of the hold-up problem. At a first stage, one agent decides on the level of a relationship-specific investment. There is no contract, so at a second stage the agent must bargain with a trading partner over the surplus that the investment has generated. We show that the conventional underinvestment result hinges crucially both on the assumed bargaining game and on the choice of equilibrium concept. In particular, we prove the following two results. (i) If bargaining proceeds according to the Nash demand game, any investment level is subgame perfect, but only efficient outcomes are stochastically stable. (ii) If bargaining proceeds according to the ultimatum game (with the trading partner as proposer), only the minimal investment level is subgame perfect, but any investment level is stochastically stable.