试解国际比较项目中的购买力平价:结果为何如此不同?

Trying to Understand the PPPs in ICP2011: Why are the Results so Different?

购买力平价汇率(PPP)是一国综合价格相对货币基准国(通常是美国)的价格指数。2014年,ICP2011发布,PPP与ICP2005的推算结果截然不同,其差异最终会对佩恩表和生活水平的国际比较产生重大影响。本文研究了这种情况发生的原因,发现问题可能出在ICP2005中区域的链接方式上。两种方法测量显示,2005年亚太(日本除外)、西亚、非洲国家对美国的消费支出PPP高估了18%—26%。

Purchasing power parity exchange rates, or PPPs, are price indexes that summarize prices in each country relative to a numeraire country, typically the United States. In 2014, the ICP published PPPs from the 2011 round that are sharply different from those that were expected from extrapolation of the previous round, ICP 2005. These discrepancies will eventually have important implications for the Penn World Table, and for international comparisons of living standards. This paper investigates why this happened. We identify a likely source of the problem in the way that the regions of the ICP were linked in 2005. We use two different methods for measuring the size of the effect. Both suggest that the 2005 PPPs for consumption for countries in Asia（excluding Japan）, Western Asia, and Africa were overstated relative to the US by between 18 to 26 percent.