Millions of villagers in Bangladesh are chronically exposed to arsenic by drinking contaminated water from private wells. Free testing for arsenic has been shown to encourage households with unsafe wells to switch to safer sources that are often within walking distance. However, the safety status of millions of tubewells remains unknown because there is no well-established market for well tests and wells continue to be installed. We describe results from a cluster randomized controlled trial conducted in 112 villages in Bangladesh, to determine, first, to what extent charging a modest fee for an environmental test limits demand. Second, we evaluate whether either informal interhousehold  agreements to share water from wells that are found to be safe, or visual reminders of well status in the form of metal placards mounted on the well pump, can increase risk-mitigating behavior. At a price of about USD0.60, only one in four households purchased a test and sales were not increased by risk-sharing agreements or visual reminders. However, switching away from an unsafe wells almost doubled in response to agreements or placards relative to the one in three proportion of households who switched away from an unsafe well after only purchasing a test.

Joint work with Ricardo Maertens, Kazi Matin Ahmed, Alexander van Geen
JEL: I12, I15, I18, Q53
Key words: Arsenic, Bangladesh, Environmental Health Risk