I hear this topic discussed quite often, yet rarely does this 2006 paper by Darius Lakdawalla, “The Economics of Teacher Quality,” come up in the popular conversation. Here is the abstract:
Concern is often voiced about the quality of American schoolteachers. This paper suggests that, while the relative quality of teachers is declining, this decline may be the result of technological changes that have raised the price of skilled workers outside teaching without affecting the productivity of skilled teachers. Growth in the price of skilled workers can cause schools to lower the relative quality of teachers and raise teacher quantity instead. Evidence from the National Longitudinal Survey of Youth demonstrates that wage and schooling are good measures of teacher quality. Analysis of U.S. census microdata then reveals that the relative schooling and experience-adjusted relative wages of U.S. schoolteachers have fallen significantly from 1940 to 1990. Moreover, class sizes have also fallen substantially. The declines in class size and in relative quality seem correlated over time and space with growth in the relative price of skilled workers.
The jstor link is here, this version is (I think) ungated for you. Here is an ungated, earlier version with some related results. Here is a good sentence from the middle of the paper:
Both schooling and experience-adjusted wages entered a period of relative decline for teachers beginning with the cohorts entering the labor force during the 1950s.
On pp.318-318 Lakdawalla discusses the importance of superior labor market opportunities for women for the argument. Here is Lakdalla’s earlier argument that Medicare benefits the poor to a disproportionate degree.
I was reminded of the education paper by a tweet from Austan Goolsbee.