In economic experiments where participants can voluntarily contribute to a group fund that benefits everyone equally, a common finding is that average contributions are initially quite high but tend to decrease over successive rounds. What does this observed pattern suggest about pure altruism as a sole explanation for cooperative behavior?

Evaluating Explanations for Cooperative Behavior

Challenging the Altruism Hypothesis in Group Contributions

In an experiment where individuals can repeatedly contribute to a group fund, the behavior of a purely altruistic participant would be to lower their contributions if they notice that other participants are not contributing their fair share.

Evaluating the 'Pure Altruism' Hypothesis

In an experiment, participants can repeatedly and anonymously contribute money to a group fund. The total fund is then multiplied and distributed equally among all participants, regardless of their individual contribution. Match each observed behavioral pattern with its implication for the hypothesis that cooperation is driven solely by pure altruism.

A key piece of evidence that challenges the theory of pure altruism in group contribution experiments is the observed tendency for contributions to _________ over successive rounds, a pattern that is inconsistent with the expectation that a truly altruistic individual would continue to contribute for the group's benefit regardless of others' actions.

An experiment is conducted over several rounds. In each round, participants can anonymously contribute from a personal endowment to a group fund. This fund is then multiplied and shared equally among all participants. Arrange the following sequence of events and interpretations to form a logical argument that challenges the idea that participants' behavior is driven solely by selfless concern for the group's welfare.

Evaluating an Economist's Conclusion

In a multi-round experiment, a group of individuals can anonymously contribute money from a personal endowment to a common pool. The total in the pool is then multiplied and distributed equally among all participants, regardless of their individual contribution. In the first round, the average contribution is relatively high. Before the second round, all participants are shown the individual contribution levels from the first round, revealing that several individuals contributed nothing. What is the most likely change in the average contribution for the second round, and what does this suggest about pure, unconditional altruism as the sole motivator?

Reciprocity as an Explanation for Declining Contributions in Public Good Games