Charitable giving and nonbinding contribution-level suggestions: Evidence from a field experiment

When asking for donations, charitable organizations often use suggestions concerning the amount of potential contributions. However, the evidence concerning the effects of such suggestions is scarce and inconsistent. Unlike the majority of existing studies concerned with small-money solicitations, we examine the effect of larger nonbinding suggestions in the context of middle-range donations which are relevant in practice. In our randomized field experiment, opera visitors received solicitation letters asking to support a social youth project organized by the opera house. The three different treatments were: no suggestion and suggestions of €100 and €200, respectively. Both suggestions were larger than average and median donations in this context. The findings are that suggestions substantially influence the distribution of donations received. The mean amounts given increase significantly if a suggestion is made. The increase is stronger in the €200 treatment. On the other hand, the participation rate decreases if a suggestion is made. Overall, the returns from the campaign increase non-significantly when a suggestion is made. The solicitation was repeated a year later, without any suggestion. There is weak evidence that suggestions have a long-term effect on individual contribution-level decisions.