When I was in high school, my economics class read The End of Poverty by Jeffrey Sachs. The book is a passionate appeal to help those living in the worst poverty in the world. Sachs writes that we should not worry too much about the people in second-to-last place, such as the poorly paid workers in labor-intensive industries who were then the focus of considerable debate and activism on U.S. college campuses. Sweatshop workers, Sachs conceded, were on the bottom rung of the ladder. But subsistence farmers were not on the ladder at all. Once we helped them get a foothold, they could begin asc...