Using price data from the Philippines, we calculated the cost of the cheapest diet sufficient to give 2,400 calories, including 10 percent calories from protein and 15 percent calories from fat. It would cost only 21 cents at PPP, very affordable even for someone living on 99 cents a day. The catch is, it would involve eating only bananas and eggs. . . . But it seems that so long as people are prepared to eat bananas and eggs when they need to, we should find very few people stuck on the left part of the S-shaped curve, where they cannot earn enough to be functional.
