Global Inequality of Opportunity: How Much of Our Income Is Determined by Where We Live?
研究发现，仅凭居住国和该国收入分布这两个个人无法控制的因素，就能解释全球按家庭人均收入分组的1%人口收入差异的一半以上，说明努力或运气对全球收入分布的解释力有限。
Suppose that all people in the world are allocated only two characteristics over which they have (almost) no control: country of residence and income distribution within that country. Assume further that there is no migration. We show that more than one-half of variability in income of world population classified according to their household per capita in 1% income groups (by country) is accounted for by these two characteristics. The role of effort or luck cannot play a large role in explaining the global distribution of individual income. © 2015 The President and Fellows of Harvard College and the Massachusetts Institute of Technology