Bright Lines, Risk Beliefs, and Risk Avoidance: Evidence from a Randomized Intervention in Bangladesh

We randomized 43 villages in Bangladesh to receive information on well-water arsenic that emphasized water safety relative to the national standard (bright-line message) or provided additional information on how risks from exposure increase with arsenic levels (gradient message). The gradient message led to 50% more switching of water sources when the arsenic level was moderately unsafe, but 40% less switching at high arsenic levels. The differences in behavior are at least partially explained by differences in risk perception that developed after the information campaign.