Abstract

We estimate flexible child health production functions to investigate whether more hygienic environments, characterized by better water, sanitation, and hygiene (WASH) practices, make nutrition intake more productive for the physical growth of children aged 6–24 months. Using 10 rounds of exceptionally rich longitudinal Filipino cohort data, we estimate value-added production functions with a control function approach. We show that WASH and nutrition are complements in the formation of child height and weight. Nutritional and WASH conditions faced by sample children are similar to those currently encountered by poor children in low-income settings with comparable stunting rates. © 2025 The University of Chicago. This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License (CC BY-NC 4.0), which permits non-commercial reuse of the work with attribution. For commercial use, contact [email protected].