Cost of college degree, 1970s, in 2005 $$: 51,348$
Median per year income for someone without a degree: 42,697
Median for someone with: 51,223
Expected lifetime earning from 18-65 for someone without:
47 * 42,697= 2,006,759$
Expected lifetime earning from 22-65 for someone with:
43*52,223 – 51,348*4= 2,194,241
Lifetime difference: Fairly trivial.
Cost of college degree, today: 108,000$
Median per year income for someone without a degree: 30,400
Median for someone with: 50,700
Expected lifetime earning from 18-65 for someone without: 1,428,800
Expected lifetime earning from 22-65 for someone with: 2,072,100
Lifetime difference: far more significant.
(Obviously, the numbers reflect a number of simplifications and generalizations. For example, some people get grants to offset the cost of college–but other people get loans, which have to be repaid with interest.)
Sadly, the increase in # of people going to college does not appear to have benefited us as a society.
(Numbers from "Strapped" by Tamara Draut.)