Global Inequality: Relatively Lower, Absolutely Higher
使用世界收入不平等数据库1975-2010年数据，发现全球相对不平等下降，但绝对不平等持续上升，且中等指标也显示不平等加剧，提出绝对不平等难以回到1975年水平。
Abstract This paper measures trends in global interpersonal inequality during 1975–2010 using data from the most recent version of the World Income Inequality Database (WIID). The picture that emerges using ‘absolute,’ and even ‘centrist’ measures of inequality, is very different from the results obtained using standard ‘relative’ inequality measures such as the Gini coefficient or Coefficient of Variation. Relative global inequality has declined substantially over the decades. In contrast, ‘absolute’ inequality, as captured by the Standard Deviation and Absolute Gini, has increased considerably and unabated. Like these ‘absolute’ measures, our ‘centrist’ inequality indicators, the Krtscha measure and an intermediate Gini, also register a pronounced increase in global inequality, albeit, in the case of the latter, with a decline during 2005 to 2010. A critical question posed by our findings is whether increased levels of inequality according to absolute and centrist measures are inevitable at today's per capita income levels. Our analysis suggests that it is not possible for absolute inequality to return to 1975 levels without further convergence in mean incomes among countries. Inequality, as captured by centrist measures such as the Krtscha, could return to 1975 levels, at today's domestic and global per capita income levels, but this would require quite dramatic structural reforms to reduce domestic inequality levels in most countries.