Researchers evaluated the impact of light-touch psychological interventions on health and economic outcomes, with a particular focus on the chlorination of drinking water. After twelve weeks, visualizing the future increased objectively measured chlorination; it also reduced diarrhea episodes among children and increased savings. After almost three years, it increased chlorination, savings, and labor supply, while effects of the planning intervention were weaker.

Researchers conducted a randomized evaluation to measure the impact of a school-based program that used a non-monetary penalty and regular monitoring to prevent adolescent tobacco use. The program reduced the probability that adolescents smoked, with effects sustained three months after the program ended. Incorporating a school competition component to the program had no further impact on smoking abstinence.