Scaling Charitable Incentives: Policy Selection, Beliefs, and Evidence from a Field Experiment

TL;DR

This study investigates why weak-evidence interventions are adopted by examining a field experiment on charitable incentives for physical activity in Japan, revealing overpredicted effects and complex stakeholder beliefs influencing policy decisions.

Contribution

It provides empirical evidence on the limited effectiveness of charitable incentives and highlights the role of stakeholder beliefs and multidimensional objectives in policy adoption.

Findings

Financial incentives increased daily steps by about 1,000.

Charitable incentives showed no significant effect.

Stakeholders overpredict incentives' effects.

Abstract

Why are interventions with weak evidence still adopted? We study charitable incentives for physical activity in Japan using three linked methods, including a randomized field experiment (N=808), a stakeholder belief survey (local government officials and private-sector employees, N=2,400), and a conjoint experiment on policy choice. Financial incentives increase daily steps by about 1,000, whereas charitable incentives deliver a precisely estimated null. Nonetheless, stakeholders greatly overpredict charitable incentives' effects on walking, participation, and prosociality. Conjoint choices show policymakers value step gains as well as other outcomes, shaping policy choice. Adoption thus reflects multidimensional beliefs and objectives, highlighting policy selection as a scaling challenge.