how much the quality of individual teachers matters over the long term.

BIG STUDY LINKS TEACHERS TO LASTING GAIN
WASHINGTON — Elementary- and middle-school teachers who help raise their students’ standardized-test scores seem to have a wide-ranging, lasting positive effect on those students’ lives beyond academics, including lower teenage-pregnancy rates and greater college matriculation and adult earnings ,according to a new study that tracked 2.5 million students over 20 years. The paper, by Raj Chetty andJohn N. Friedman of Harvard and Jonah E. Rockoff of Columbia, all economists, examines a larger number of students over a longer period of time with more in-depth data than many earlier studies, allowing for a deeper look at how much the quality of individual teachers matters over the long term. The article is in The New York Times.