In this TED talk, Myriam Sidibe discusses the public health effects of hand-washing. She makes an interesting and important claim: a lot of families in India have soap, but they use it to wash clothes, bathe, and wash dishes because they view soap as a precious commodity.

This increases my confidence that Bryan is exactly right: we’re neglecting the obvious: do we get more bang for our buck by redistributing wealth, training public health workers, or by encouraging the economic growth that will give people the incomes they need to buy more soap and install indoor plumbing (here’s a brief primer on the equal marginal principle to illustrate the trade-offs)?