209096 Trickle Down: Diffusion of Chlorine for Drinking Water Treatment in Kenya

Monday, November 9, 2009: 11:06 AM

Michael Kremer, PhD , Department of Economics, Havard University, Cambridge, MA
Edward Miguel, PhD , Department of Economics, University of California, Berkeley, Berkeley, CA
Sendhil Mullainathan, PhD , Department of Economics, Havard University, Cambridge, MA
Clair Null, PhD , Rollins School of Public Health, Hubert Department of Global Health, Emory University, Atlanta, GA
Alix Peterson Zwane, PhD , Goggle.Org, Mountain View, CA
We study the distribution of dilute sodium hypochlorite to treat drinking water in homes in rural Kenya. Using a randomized evaluation, we find large impacts of receiving a six-month supply of free chlorine. At the time of follow-up, 58% of treatment households had detectable chlorine in home water on an unannounced visit and there was a 69% reduction in water contamination as measured by the fecal indicator bacteria E. coli. Child diarrhea rates fell by 35-40%. However, data from a subset of households given coupons for discounted chlorine in local shops indicate that demand for the product is very low at even a small cost. We do not find that households with young children, who stand to benefit most from cleaner water, have a higher valuation for it. Based on exogenous variation in the proportion of study households in a given community who were included in the treatment group, we find that the effect of social networks on adoption is moderate in comparison to the take-up impacts of getting free chlorine. In a follow-on study, we analyze social marketing messages, chlorine promoters, and installation of chlorine dispensers at water collection points as alternate means of encouraging adoption. Consistent with our earlier results, price seems to be a major impediment to use. Of the methods we evaluate, chlorine dispensers offer by far the greatest promise for sustainable adoption at scale by drastically reducing the cost of supplying communities with free chlorine and harnessing social network effects.

Learning Objectives:
Describe results from a randomized evaluation of dilute chlorine for point-of-use water treatment in rural Kenya. Assess household demand for chlorine. Evaluate role of social networks in household decision to chlorinate drinking water. Identify cost-effective means of encouraging households to chlorinate their drinking water.

Keywords: Drinking Water Quality, Cost-Effectiveness

Presenting author's disclosure statement:

Qualified on the content I am responsible for because: Ph.D. in Agricultural & Resource Economics; co-author on this paper which I have presented at a number of other venues (Rollins School of Public Health at Emory University, Center for International Health and Development at Boston University, University of California Berkeley, etc.)
Any relevant financial relationships? No

I agree to comply with the American Public Health Association Conflict of Interest and Commercial Support Guidelines, and to disclose to the participants any off-label or experimental uses of a commercial product or service discussed in my presentation.