Poor water quality is a leading cause of illness and death in the developing world, killing many children every year and presenting a particular challenge in rural areas, where providing sustainable access to safe drinking water is especially difficult. Piped treated water, which produced substantial health gains in developed countries and some urban areas in developing countries, is not considered feasible in rural areas of developing countries with dispersed populations and weak institutions for maintenance. Community interventions short of piped water, such as spring improvement or communal wells, have not produced strong results. Thus policy-makers and private enterprises interested in providing safe water to rural populations are increasingly interested in household and point-of-use treatments.

This study will evaluate demand for and impacts of one household lever water improvement technology: the Kosim filter, a ceramic filter marketed and sold by Pure Home Water (PHW), a Ghana-based NGO. This simple product has been demonstrated to be highly effective at improving water quality and is appropriate for the study region, since it does not require electricity.

We will offer individual rural households the opportunity to purchase the filter at randomized prices, uncovering true willingness to pay through our elicitation mechanism. By staggering the sale of the product within villages and mapping social networks carefully, we will provide new evidence on the evolution of demand for health goods. Furthermore, the randomized offer price provides an instrument for unbiased estimation of the filter's health impact and health spillovers among neighbors.

We will address several key questions. First, we will provide evidence on the health effects of household-level water treatment in poor rural areas with high waterborne disease loads. Second, we will measure households' willingness to pay for in-home water treatment. Third, we will inform optimal pricing strategy for the introduction of consumer durables when social objectives must be balanced with financial sustainability. Finally, we will advance the research frontier by using leading technologies for testing household water quality and a sophisticated evaluation technique, the Becker Degroot Marschak (BDM) mechanism,  that is meant to uncover households' true willingness to pay. This study will be among the first to use the BDM technique in a true field setting.