Democracy delivers the tap. But not always the safe water.

Roughly 2 billion people still lack reliable access to clean drinking water.

Shouldn’t this be a priority for governments around the world? At least a generation of social scientists has argued that democracies should perform better in delivering basic human services because citizens can apply pressure on their leaders. Competitive elections, a free press, and an active civil society are tools to hold politicians accountable. For many outcomes, the story largely holds. In a new paper just published in World Development, Evan Lieberman and Naomi Tilles test whether it holds for water.

The answer, it turns out, depends entirely on what you mean by “water.”