Too many charities? Insight from an experiment with multiple public goods and contribution thresholds

We present results from an experiment with multiple public goods, where each good produces benefits only if total contributions to it reach a minimum threshold. The experiment allows us to compare contributions in a benchmark treatment with a single public good and in treatments with more public goods than can be funded. The presence of multiple public goods makes coordination among participants more diffcult, discouraging contributions, and decreasing the likelihood of any public good being effectively funded. Multiplicity decreases funding unless one public good stands out as being the most efficient alternative. Applied to the case of philanthropy, the results show how overall donations and the number of effectively funded charities may both decrease as the total number of charities increase. This is true even if the new charities offer higher potential benefits than previous options.