In more unequal countries, children's incomes track their parents' more closely
Economist Miles Corak compared countries and found that where income inequality is higher, a child's earnings are more closely tied to their parents', meaning less social mobility. Alan Krueger, then chair of the US Council of Economic Advisers, named the pattern the 'Great Gatsby curve' in 2012. It's a correlation, and economists still debate how much inequality itself causes lower mobility.