Treating water can reduce the prevalence of diarrhoea by up to 70 percent. Although there are several inexpensive water treatment technologies available, statistics show that every 15 seconds a child dies due to waterborne diseases. Over 700 million people still lack access to safe drinking water. While there is a lot of research on the effectiveness of water treatment technologies, we urgently need to build on our understanding of the factors that contribute to the demand for and adoption of these products. The second issue of the 3ie-IDS brief Evidence Matters addresses crucial questions related to this development conundrum - Are people willing to pay for clean water? Is pricing the only factor influencing how people view its benefits? This brief distills policy relevant messages from a recent 3ie systematic review by Null, C., Kremer, M., Miguel, E., Garcia Hombrados J., Meeks R., and Zwane Alix to answer these questions. The evidence cited here is drawn from research in Bangladesh, Ghana, Kenya and Zambia.

Key policy messages:

1- Many people are not willing to pay for safe drinking water. Even paying a small fee puts people off using water treatment technologies. 2- Understanding why people are not keen to pay and how much they might pay if they had the right information could help overcome these barriers. 3- Subsidising the costs of water treatment technologies can improve their uptake, but large subsidies are required. 4- Cheaper and innovative technologies and distribution models may encourage people to change their behaviour and start using water treatment technologies which would improve their health.