Two groups participate in an experiment where they can contribute to a shared project over ten successive rounds. In each round, the total contributions are increased by a fixed percentage and then distributed equally among all participants, regardless of their individual contributions.

• Group A has no mechanism to influence each other's earnings. Their average contribution starts high but steadily decreases with each round.
• Group B is informed that a mechanism exists allowing them to penalize low contributors, but records show this mechanism is very rarely used. Despite this, Group B's average contribution remains consistently high across all ten rounds.

What is the most likely explanation for the difference in outcomes between the two groups?

Evaluating Strategies for a Community Project

The Power of Potential Consequences

Mechanisms for Sustaining Cooperation

In a repeated public goods game, for a punishment mechanism to successfully sustain high levels of contribution, it is essential that low contributors are frequently and consistently penalized by other group members.

A group of participants plays a public goods game for 20 rounds. For the first 10 rounds, there is no mechanism for penalizing low contributors, and average contributions steadily decline. Before round 11, the researchers announce that a costly punishment option is now available, allowing participants to reduce the earnings of others at a personal cost. Based on findings from similar experiments, what is the most likely change in behavior from round 11 onwards?

Comparing Enforcement Strategies for a Shared Resource

Evaluating Community Contribution Strategies

Evaluating a Low-Cost Compliance Strategy

A manager observes that a shared office kitchen is frequently left untidy, as many employees do not clean up after themselves. This forces a few responsible employees to do most of the cleaning. The manager wants to encourage more cooperative behavior with minimal intervention. Based on principles of sustaining cooperation, which of the following actions is most likely to be effective while requiring the least ongoing effort?

Mechanisms for Sustaining Cooperation