Cameron Peng, from LSE, will present his research. 

Diminishing Returns to Intervention: Evidence from a Large-Scale RCT on Investor Trading

We study how the frequency of behavioral interventions affects retail investors' trading decisions. In a large-scale RCT over 3 months on a major fund distribution platform in China, we randomly vary the probability that a popup intervention appears when investors attempt to redeem equity funds. Popups reduce redemption amounts by 9–12%, but the effect is flat beyond the lowest treatment intensity—a light, infrequent intervention achieves nearly the same effect as a heavy one. This flat dose-response holds for deterring redemptions, while encouraging fund conversion requires higher frequency. Effects are localized, with no spillover to non-targeted assets, and disappear once interventions cease.