Cross-Country Income Levels over Time: Did the Developing World Suddenly Become Much Richer?
研究了2011年全球相对价格调查中低收入国家收入水平大幅上升的现象，通过构建反事实价格来统一2005年和2011年的测量方法，发现2005年调查高估了国际收入不平等。
The latest global survey on relative prices and income levels, for the year 2011, showed changes to relative income levels that were larger in lower income countries, thereby narrowing the world income distribution compared to estimates based on the previous, 2005, survey. This paper examines whether changes in measurement methodology between the 2005 and 2011 survey can explain these large differences. We construct a counterfactual set of relative prices for 2005 that harmonizes measurement, and we no longer find systematic differences across income levels, implying that international income inequality based on the 2005 survey was overstated.