Finally, between 1967 and 2017, the premium in earnings received for having a college degree nearly doubled. We can compute the effect of that higher premium by adding the premium increase to the average hourly earnings for each quintile’s college graduates. The result of all these changes to the 1967 data (proportion of people working, hours worked, educational attainment, and college premium) is a Gini coefficient of 0.572, an increase of 29.2 from 1967, which means that adding the higher college premium explains about a 5.2 percent increase in earned-income inequality.
