The Evidence Effect

Evidence in action

The Evidence Effect highlights 31 examples of life-changing programs that warrant more attention, investment, and consideration for scaling. Explore them below, drawn from more than 1,200 completed randomized evaluations led by researchers in our network.

Providing regular deworming pills for children helps them stay in school, learn more, and earn more as adults. 

A child’s earliest years shape lifelong outcomes. To boost children’s development, invest in programs that help parents interact with babies and toddlers in stimulating ways.

A child’s earliest years shape lifelong outcomes. To boost children’s development, invest in programs that help parents interact with babies and toddlers in stimulating ways.

Meeting children where they are helps them catch up in school.

Meeting children where they are helps them catch up in school.

Many more people use products like mosquito nets, water-purifying chlorine tablets, and deworming pills when they are free.

Many more people use products like mosquito nets, water-purifying chlorine tablets, and deworming pills when they are free.

Investing in girls’ secondary education can have big payoffs for girls and for the next generation.

An entertaining television drama series led young adults to adopt safer sexual health practices—succeeding where other public health campaigns have struggled.

Abhijit Banerjee and Esther Duflo joint headshot

The objectives of aid are often unclear.... Reaffirming the most basic principle would provide clarity: The goal should be to invest in projects that will have the largest impact on the quality of life of poor people around the world.

—Abhijit Banerjee and Esther Duflo, The Financial Times, March 2025

Discover more perspectives from the J-PAL network

 


Acknowledgements: The Evidence Effect content was developed by many J-PAL authors, with leadership from Alison Fahey, Ying Gao, Eliza Keller, and Lisa de Rafols. The microsite was designed by Elizabeth Bond and illustrations were created by Lucy Nguyen. We are grateful for John Martello's vision and support in enabling this project.

Suggested citation: Abdul Latif Jameel Poverty Action Lab (J-PAL). 2025. “The Evidence Effect.” Last modified: July 2025. www.povertyactionlab.org/evidence-effect 

Photos: (1) Two farmers uproot rice seedlings for transplantation during monsoon season in India. Credit: Shutterstock.com; (2) A woman laughs as an enumerator measures her height in her home in Borong, East Nusa Tenggara, Indonesia. The measurement was part of an impact evaluation of an information campaign focused on preventing malnutrition. Credit: Miranda Putri, J-PAL;  (3) Credit: Official, Shutterstock.com