The Economics of Teacher Quality

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.