The Heterogenous Effects of Nudges to Promote Early Evacuation

Abstract

This study replicates the main result (s) of a previous study and analyzes heterogeneity by using the results of a randomized controlled trial conducted in Hiroshima Prefecture to validate nudges in order to promote early evacuation in the event of a heavy rain disaster. The main findings of the experiment are as follows: 1) previous studies underestimated the effect of the messages by 2 to 4 percentage points, but the conclusion remains the same that messages conveying information about the externality of evacuation behavior and appealing to altruism using loss expressions were the most effective. 2) Machine learning analysis shows no heterogeneous effects of nudges. 3) Messages conveying the benefits of an evacuation to a shelter in terms of gains were more effective for those with a negative impression of the shelter, while messages conveying the same information in terms of losses showed no heterogeneity. 4) Heterogeneity existed depending on how participants interacted with the local community. This was not seen, however, in the workplace.