"There's Money in Thirst," reads a headline in the New York Times. The CEO of Nestl , purveyor of bottled water, heartily agrees. It is important to give water a market value, he says in a promotional video, so "we're all aware that it has a price." But for those who have no access to clean water, a fifth of the world's population, the price is thirst. This is the frightening landscape that Karen Piper conducts us through in The Price of Thirst--one...