The magnitude of variation in the quality of teachers, even within each school, is startling. Teachers who work in a given school, and therefore teach students with similar demographic characteristics, can be responsible for increases in math and reading levels that range from a low of one-half year to a high of one and a half years of learning…

We provide evidence that the robust association between cognitive skills and economic growth reflects a causal effect of cognitive skills and supports the economic benefits of effective school policy. We develop a new common metric that allows tracking student achievement across countries, over time, and along the within-country distribution.…

Most analyses of teacher quality end without any assessment of the economic value of altered teacher quality. This paper combines information about teacher effectiveness with the economic impact of higher achievement. It begins with an overview of what is known about the relationship between teacher quality and student achievement, which provides…