More than two billion people around the world do not have safe drinking water at home. Piped water infrastructure remains out of reach for much of the developing world, and cheaper alternatives like chlorine tablets have low take-up rates even when given away for free.

In a paper in the American Economic Review, authors Fiona Burlig, Amir Jina, and Anant Sudarshan explore a third option. Working with a private company in rural Odisha, one of India's poorest states, the researchers ran a randomized experiment across roughly 60,000 households to test the effectiveness of delivering treated water directly to people's doors.

Burlig recently spoke with Tyler Smith about revealed-preference measurements of the value of clean water and steps governments might take toward reaching the goal of universal access.