A Field Experiment in Charitable Contribution: The Impact of Social Information on the Voluntary Provision of Public Goods
通过实地实验发现，社会信息（他人捐赠额）会正向影响个人捐赠，尤其是对首次捐赠者效果显著，且不会挤出未来捐赠。
We study the effect of social information on the voluntary provision of public goods. Competing theories predict that others' contributions might be either substitutes or complements to one's own. We demonstrate a positive social information effect on individual contributions, supporting theories of complementarities. We find the most influential level of social information is drawn from the 90th to 95th percentile of previous contributions. We furthermore find the effect to be significant for new members but not for renewing members. In the most effective condition, social information increases contributions by 12% ($13). These increased contributions do not crowd out future contributions. Copyright © The Author(s). Journal compilation © Royal Economic Society 2009.