In a large-scale natural experiment with over 14,000 individuals, we investigate whether public transport usage can be influenced by social norms and by economic incentives. Despite their effectiveness in other domains, we find a tightly estimated zero for descriptive social norms on ridership. Increasing the economic incentive, by doubling the trial period, significantly increases uptake and long-term usage. This increase is sustained for months after removing the incentive. The effect is mainly driven by initial low users, which is evidence for habit formation and highlights the heterogeneous effects of the policy. While there is scope for long-term behavior change, norm nudges might not be the most promising approach.

在超过 14,000 人的大规模自然实验中，我们调查了公共交通的使用是否会受到社会规范和经济激励的影响。尽管它们在其他领域很有效，但我们发现对乘客量的描述性社会规范严格估计为零。通过将试用期加倍来增加经济激励，显着增加了吸收和长期使用。在取消激励措施后，这种增长会持续数月。效果主要由初始低用户驱动，这是习惯形成的证据，突出了政策的异质效应。尽管存在长期行为改变的空间，但规范推动可能不是最有希望的方法。