The challenge
Dirt floors are hard to clean, so faecal matter stays on them and spreads parasites to people, especially young children.
The case
Piso Firme, a Mexican government program to replace dirt floors in the homes of disadvantaged urban families, offers households up to 50 square metres of concrete flooring. It was first implemented as a local program in the State of Coahuila, and since 2000 it has installed cement floors in about 300,000 of the estimated 3 million homes that had dirt floors. Researchers from the University of California, Berkeley, the World Bank and others compared families in the city of Torreón, Coahuila, with similar families across the state border in Gómez Palacio and Lerdo, Durango, where the program hadn't yet arrived. They estimated that fully replacing dirt floors with cement led to a 78% reduction in parasitic infestations, a 49% reduction in diarrhoea and an 81% reduction in anaemia in children, and improved their cognitive development. Adults were more satisfied with their housing and quality of life and had lower depression and stress scores.
Why it worked
A simple, one-off home improvement delivered large health gains for young children. The study used a natural border comparison rather than random assignment, though the two areas were very similar.
Sources
- Cattaneo, M. D., Galiani, S., Gertler, P. J., Martinez, S., & Titiunik, R. (2009). Housing, health, and happiness. American Economic Journal: Economic Policy, 1(1), 75–105.
- World Bank Policy Research Working Paper 4214 (earlier version, with full estimates), same title.
Spot an error or know a better source? Tell us