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Study of the Distribution of Effective Teaching

Contract Information

Current Status:

This study has been completed.


September 2010 – March 2018



Contract Number:



Mathematica Policy Research
American Institutes for Research


There is a persistent achievement gap in the United States where students from high-income families outperform those from low-income families on achievement tests. There is also substantial variation in the effectiveness of teachers available to students. A key question for policy makers is whether there is inequitable access to effective teachers and, if so, could providing equal access to effective teachers reduce the achievement gap. This study provided information about the extent to which disadvantaged students received less-effective teaching than other students. The study also examined teacher mobility in participating districts and how patterns of mobility might contribute to unequal access.

  • Are low-income students taught by less effective teachers than high-income students? If so, to what extent would providing equal access to effective teachers reduce the student achievement gap?
  • Are there differences between high- and low-poverty schools in teacher hiring, transfer, and attrition? If so, are they consistent with inequitable access to effective teachers for low-income students?

This study was descriptive, documenting low-income students' access to effective teachers, as measured by value added across the 2008–2009 through 2012–2013 school years in 26 geographically-dispersed school districts. The study also described district polices designed to address an inequitable distribution of effective teaching implemented during the same school years, 2008-2009 through 2012-2013. Lastly, the study examined teacher mobility patterns within participating districts.

Data collection included district administrative records such as student achievement to conduct value-added analyses (to address the first research question), as well as annual semi-structured interviews with district leadership to provide information on district policies. District personnel data was also collected to examine teacher mobility within participating districts (to address the second research question).

The final report based on five school years of data (2008–2009 to 2012–2013), titled Do Low-Income Students Have Equal Access to Effective Teachers? Evidence from 26 Districts, and a study snapshot were released in October 2016.

Other publications related to this study are listed below:

Do Disadvantaged Students Get Less Effective Teaching? A brief synthesizing recent IES research studies on effective teaching, and video (January 2014)

Access to Effective Teaching for Disadvantaged Students A report based on three school years of data (2008–2009 to 2010–2011) from 29 districts, a study snapshot, and video (November 2013)

  • There are small differences in the effectiveness of teachers of high- and low-income students, on average. The average teacher of a low-income student is just below the 50th percentile of effectiveness based on value-added, while the average teacher of a high-income student is at the 51st percentile. Providing low-income students with equally effective teachers would not substantively reduce the achievement gap.
  • In a subset of the study districts, there is meaningful inequity in teacher effectiveness in math. In three of the 26 study districts, providing low-income students with teachers whose effectiveness is equal to that of high-income students over a five-year period would reduce the math achievement gap by at least a tenth of a standard deviation of student achievement, the equivalent of about 4 percentile points.
  • Teacher hiring and transfer patterns are consistent with small inequities in access to effective teachers. High-poverty schools have more newly hired teachers than low-poverty schools, but this difference likely has a small influence on equity because (1) relatively few teachers are new hires, and (2) performance of newly hired teachers improves quickly. Teachers who transfer to schools in a higher poverty category are less effective than the average district teacher. Teachers who transfer to schools in a lower poverty category are nearly as effective as the average district teacher. These patterns likely have a small influence on equity since just under 4 percent of all teachers transfer across poverty categories each year.
  • Teacher attrition patterns do not contribute to inequity. Teachers who leave a district are less effective than the average teacher and more teachers leave high-poverty schools than low-poverty schools.