[12] In 2004, Kremer and co-author Edward Miguel published an impact evaluation of a school-based deworming campaign in Kenya, showing that the program increased school attendance rates by 25% and improved overall health.

Alix Zwane, Evidence Action's first executive director,[15] articulated the organization's mandate as being based on the "gap between what research shows is effective in global development and what is implemented in practice.

In 2015, Alexander Aiken and co-authors published two papers in the International Journal of Epidemiology reproducing Kremer and Miguel's results with both the same and different methods,[28][29] showing less pronounced effects on attendance and no impact on school performance.

[30][31] In 2015, an article in PLOS Neglected Tropical Diseases criticized the Cochrane review,[32] arguing that it included an unnecessarily limited number of studies, and that RCTs often understate effects by treating both those with heavy and light worm burdens.

[31] This assessment was further supported by a long-term follow-up published by Miguel, Kremer, and co-authors in the Proceedings of the National Academy of Sciences, showing that children treated with deworming medications twenty years prior have higher earnings, and are more likely to work in non-agricultural jobs.

[35] In light of these results, Evidence Action continues to implement deworming programs, treating 275 million children annually in Kenya, India, Vietnam, Nigeria and Ethiopia.

[5][14] An impact evaluation of Kenya's National School-Based Deworming Program, implemented in partnership with Evidence Action, concluded that the scheme reduced the rate of soil-transmitted helminth infection in the country by 26.5 percentage points from 2012 to 2022.

[14] In 2022-2023, Evidence Action launched a similar mass deworming program in Lagos State with the support of the Nigerian Federal Ministry of Health, aiming to treat 1.3 million children under the age of five.

The scheme was incubated by Innovations for Poverty Action, and was founded in response to a series of randomized controlled trials conducted by Michael Kremer, Edward Miguel, Sendhil Mullainathan, Clair Null, and Alix Zwane in Kenya between 2004 and 2010.

[39][40] Subsequent work by Kremer, Johannes Haushofer, Ricardo Maertens, and Brandon Joel Tan showed that this increase in chlorination take-up translated into improved health, with treatment causing a reduction in child (i.e. under five) mortality of 1.4 percentage points, a 63% decline from baseline.

[42] A subsequent meta-analysis of 52 RCTs by Michael Kremer and co-authors confirmed this result, showing that water chlorination saves disability adjusted life years at a cost of approximately $40.

[45] Evidence Action also operates an Accelerator program, whereby promising, cost-effective health and nutrition interventions are scaled and tested iteratively according to a venture capital model.

[49] Evidence Action also operates Equal Vitamin Access, a program that provides iron and folic acid supplementation to children in regions where anemia and other nutritional deficiencies are common.

[1] In 2019, Evidence Action's Beta program launched a pilot of the scheme in partnership with several Indian states with the support of a $5.1 million incubation grant from Good Ventures.

The scheme was based on a similar program studied by Gharad Bryan, Shyamal Chowdhury, and Mushfiq Mobarak in a randomized controlled trial in which Bangladeshi farm workers were given low interest loans to migrate to nearby cities.

[53][54] Mushfiq Mobarak, whose study in Econometrica promoted the program's rollout, argued that the null effect was the result of RDRS disproportionately registering those eager to migrate before the incentive was provided.

[53] The program was also called into question after Evidence Action's leadership was made aware that the initial approval of the project was solicited via a bribe to a junior government official.

As of 2023, the charity has received over 20 distinct grants from Good Ventures,[57] an American philanthropic organization founded by Cari Tuna and Dustin Moskovitz that distributes funds in line with recommendations from Open Philanthropy.