Quantity Over Quality

Concern is often voiced about the quality of American schoolteachers. This paper shows that, while the relative quality of teachers is declining, this decline is a result of skill-biased technological change, which improves the knowledge of skilled workers outside teaching, but not the general knowledge of schoolteachers. This raises the price of skilled teachers, but not their productivity. Schools respond by lowering the relative quality of teachers and raising teacher quantity. Growth in the price of teachers also raises the unit cost of primary education. These three predictions appear consistent with the data. Class sizes have dropped by more than half over the last 50 years in many developed countries. In stark contrast, analysis of US Census microdata reveals that, from the 1900 birth cohort to the 1955 birth cohort, the log earnings of male teachers-adjusted for experience and hours worked- have declined by twenty-three percentage points relative to college-educated workers, and by fifty percentage points for female teachers. Finally, over the past thirty years alone, the real per student cost of primary school education in the US has more than doubled, in spite of stagnant student achievement.