About 92 percent of 1940 babies had higher pretax household earnings at age 30 than their parents had at the same age. (The results were similar at older ages and for post-tax earnings.)
…For babies born in 1980 — today’s 36-year-olds — the index of the American dream has fallen to 50 percent: Only half of them make as much money as their parents did.
That is from David Leonhardt at the NYT, channeling new research by Raj Chetty. Here is more from Jim Tankersley. Here is Brookings coverage. Here is Vincent Geloso considering various adjustments to the data.