Unpacking the side effects of social norm nudges
通过一项2775名英国受访者的调查实验，研究社会规范助推（鼓励素食）是否会影响非目标行为（环保捐赠），发现助推虽增加素食选择，但会挤出特定人群的捐赠意愿。
Growing evidence shows that green nudges can affect secondary (non-targeted) behaviours. However, it is unclear whether such spillovers arise as a result of engaging in the targeted behaviour or if they are a by-product of policies. In a survey experiment with 2775 English respondents, we test whether a social norm nudge promoting vegetarianism alters a non-targeted action: environmental donations. Social norm messaging increases intended vegetarian choices, but not uniformly. A subgroup identified with machine learning drives this effect. However, we find the social norm nudge crowds out donations from respondents in this subgroup. Our experimental design allows us to rule out the possibility that this crowding-out effect is driven by respondents substituting climate-friendly food choices with environmental donations. This suggests that social norm nudges may work, but at the risk of discouraging other environmentally friendly actions.