What can an experiment in Maharashtra tell policymakers about the effect of sanitation on child height?
Speaker: Dean Spears, Centre for Development Economics, Delhi School of Economics
Chair: Dr Jyotsna Puri, Deputy Executive Director and Head of Evaluation Office, 3ie
Date: 13 June, 2014, 3.30-5 p.m.
Venue: ISID Complex, Plot No.4, Vasant Kunj Institutional Area, New Delhi
Most of the world's open defecation happens in India. Open defecation releases germs into the environment, where children come into contact with them. What is the effect of all of this environmental disease? This paper discusses a randomised experiment conducted by the World Bank and the Government of Maharashtra in 2004.
The evidence of the experiment suggests that reducing open defecation helps children grow taller – which is consistent with converging evidence of an effect of sanitation on child height from a variety of sources.
However, this story is more complicated than a regular field experiment, because the researchers also have comparable data on two other districts where the original research team initially planned to conduct the experiment, but ultimately did not. The district where the experiment ultimately happened had the most human development, and the data suggests that one might not expect the experimental results to be quite so positive outside of these special circumstances.
Although we believe that sanitation contributes to child growth – even in properly conducted field experiments – the study suggests that the story of this experiment should encourage reflection on the external validity of randomised evaluations, more broadly. By how much is the set of experimental evidence that we have shaped by the fact that experiments can only happen where high capacity organisations are willing and able to do them?