Today David Brooks again writes about educational attainment over time in the U.S., and I think I understand why I misunderstood his earlier columns.
The first paragraph in a recent NBER working paper by Jim Heckman says it all: "American society is polarizing. Proportionately more American youth are graduating from college than ever before. At the same time, American-born youth are graduating from high school at lower rates than 40 years ago."
If you take a quick look at the educational attainment statistics, comments like Brooks's earlier remarks about declining attainment just don't seem to hold up. This is what I originally found, but the mistake I made was looking just at college attainment, which is only relevant for about 30% or so of the workforce. Apparently closer inspection reveals this divergence in skills between the bottom and the top that Heckman and Brooks talk about.