1. Angus S. Deaton ( ) is the Dwight D. Eisenhower Professor of International Affairs and a professor of economics and international affairs at the Woodrow Wilson School, Princeton University, in New Jersey.
2. Robert Tortora was principal scientist and chief methodologist at the Gallup Organization, in Washington, D.C., when this article was written. He is now a senior fellow of survey methodology at ICF International, in Rockville, Maryland.