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. This study shows that great teachers create great value — perhaps several times their annual salaries — and that test score impacts are helpful in identifying such teachers. Nevertheless, it is clear that improving the quality of teaching — whether using value-added or other tools — is likely to have large economic and social returns.
Chetty, R., Friedman, J.N. and Rockoff, J. (2011), The Long-Term Impacts of Teachers: Teacher Value-Added and Student Outcomes in Adulthood, NBER Working Paper 17699.