Harvard logo THE LONG-TERM IMPACTS OF TEACHERS  Columbia Business School
Raj Chetty
Harvard University
  John N. Friedman
Harvard University
  Jonah E. Rockoff
Columbia University



   » Executive Summary

   » Final AER Papers (with Appendices)
        Part 1: Bias in VA Estimates
        Part 2: Long-Term Impacts

   » NBER WP 17699 [old version]         

   » Education Next article         

   » Video of Presentation

   » Presentation Slides [PPT] [PDF]

   » STATA Code

   » Press Coverage

   » Discussion of ASA Statement

   » Response to Adler (2014)

A teacher's "value-added" is defined as the average test-score gain for his or her students, adjusted for differences across classrooms in student characteristics (such as their previous scores).
Is teacher value-added a good measure of teacher quality?  

When a high value-added (top 5%) teacher enters a school, end-of-school-year test scores in the grade he or she teaches rise immediately...

... and students assigned to such high value-added teachers are more likely to go to college, earn higher incomes, and less likely to be teenage mothers. On average, having such a teacher for one year raises a child's cumulative lifetime income by $80,000 (equivalent to $14,500 in present value at age 12 with a 5% interest rate).

The earnings gains from replacing a low value-added (bottom 5%) teacher with one of average quality grow as more data are used to estimate value-added. Discounting future earnings gains to present value, the gains are $270,000 with 3 years of data. If future earnings are not discounted, cumulative earnings gains surpass $1.4 million per class.

We conclude that great teachers create great value, and that test-score based value-added measures are one useful input into identifying such teachers.


Note: The results of this study were originally disseminated as NBER Working Paper 17699 in December 2011. The final results of this study are published in the American Economic Review as two separate papers. The first paper evaluates bias in VA estimates, while the second estimates teachers' long-term impacts. The two final papers as well as the original paper are posted on this site; the STATA code corresponds to the revised manuscripts.



 Contact Web Designer