Social Comparisons and Contributions to Online Communities: A Field Experiment on MovieLens
通过实地实验，研究社会比较信息对在线社区用户贡献行为的影响，发现低于中位数的用户评分量增加530%，高于中位数的用户评分量减少62%。
We design a field experiment to explore the use of social comparison to increase contributions to an online community. We find that, after receiving behavioral information about the median user's total number of movie ratings, users below the median demonstrate a 530 percent increase in the number of monthly movie ratings, while those above the median decrease their ratings by 62 percent. When given outcome information about the average user's net benefit score, above-average users mainly engage in activities that help others. Our findings suggest that effective personalized social information can increase the level of public goods provision.