英語翻譯
Measuring the World Distribution of Income
I construct a WDI by estimating an annual income distribution for each of 138 countries and then integrating these country distributions for all levels of income.[6] The starting point of the analysis is the population-weighted income per capita,which we will use as the mean of each country’s distribution.As a measure of income,I use the purchasing power parity–adjusted GDP per capita from the Penn World Tables.[7] One could anchor the country distributions to other measures of average income,such as the mean income from surveys.I choose not to do so for a variety of reasons,including (but not limited to) the lack of survey data for many countries and time periods.Since surveys are not available every year,if one used the mean income of those surveys to anchor the mean of the distribution,then one would have to "forecast" the means for missing years.National accounts data,on the other hand,are reported by the Penn World Tables for all countries during our sample period.