Context on deworming replicability adjustment

Abstract

This document explains how to adjust research findings for “replicability” or internal validity, specifically focusing on deworming studies. When evaluating charitable programs, researchers must account for the fact that studies may not perfectly replicate or capture true program effects. The case of deworming is particularly challenging due to limited high-quality evidence, unclear impact mechanisms, and unexpectedly large effect sizes (approximately 10% income increase). These factors suggest the need to substantially discount the estimated effects. While various methods have been used to calculate deworming replicability adjustments, each has both strengths and significant limitations. Based on these considerations, an appropriate replicability adjustment for deworming studies would likely fall between 5-30% (meaning a 70-95% discount), with the specific percentage depending on various judgmental factors. In 2019, a replicability adjustment of approximately 13% was recommended for deworming studies.