The purpose of this paper is to test the absolute as well as the relative importance of these three reasons for non-selfish behavior. This is done by conducting a natural field experiment on voluntary contributions to a national park in Costa Rica.
We investigate the role of anonymity, reciprocity, and conformity for voluntary contributions, based on a natural field experiment conducted at a national park in Costa Rica. The effect of anonymity is tested by letting the subjects contribute their money either openly in the presence of the solicitor, or in a sealed envelope. The effect of reciprocity is investigated by handing over a small gift to a sub-sample of subjects, prior to their contribution decision. With reciprocity we mean that people are reciprocal if they reward kind actions and punish unkind actions towards them; cf. Falk and Fischbacher (2006) and Rabin (1993). In principle, the kindness of the action can be evaluated both in terms of the consequences and in terms of intentions (Dufwenberg and Kirchsteiger, 2004; Rabin, 1993); simply put, kind actions appreciated for their good consequences can trigger punishing behavior if the intentions are regarded as bad. We investigate the effect of conformity by providing the subjects with information about the contributions of previous subjects. The information is varied among subjects and we include the case of providing no information as well. By conformity we mean that people care about their own contribution relative to the contributions of others; see Bernheim (1994) for an example of a model of conformity where people care about their status in terms of their relative contribution to a public good.
Contributions made in public in front of the solicitor are 25% higher than contributions made in private. Giving subjects a small gift before requesting a contribution increases the likelihood of a positive contribution. At the same time, the conditional contribution decreases. The total effect of giving a gift is positive but small, and taking the cost of the gift into account, it is far from profitable. When the subjects are told that the typical contribution of others is $2 (a small contribution), the probability of a contribution increases and the conditional contribution decreases, compared with providing no reference information. Providing a high reference level ($10) increases the conditional contributions. Overall, the total effects have the expected signs, although the magnitudes are smaller than what one might have expected based on existing evidence from laboratory experiments.
