Do disadvantaged students get stuck with more-ineffective teachers than students who are well off? A new study says no.
It’s common knowledge that students from wealthy families perform better on standardized tests than students from poor families. Does this mean rich students are taught by more-effective teachers? A new study from Mathematica Policy Research, sponsored by the U.S. Department of Education’s Institute of Education Sciences, sought to answer this question. The study looked at 26 school districts and found that both rich and poor students have just about the same chances of landing in the classrooms of the most-effective teachers. They’ve also got similar odds of landing in the classroom of the least-effective teachers.
“Contrary to conventional wisdom, we found only small differences in the effectiveness of teachers of high- and low-income students in our study districts,” said Eric Isenberg, the study’s principal investigator and a senior researcher for Mathematica. “This suggests that the achievement gap arises from factors other than students’ access to effective teachers.”
The study looks at five years of English/language arts and math standardized test scores for students in grades 4 through 8 to determine which teachers were more effective, based on their students’ test-score gains, and whether rich students had more-effective teachers than poor students. The districts that participated in the study are large, with median enrollments of 70,000, and they have high percentages of low-income and minority students. Overall, 63 percent of students in the study districts qualify for free or reduced-price lunch, 29 percent are black, and 42 percent are Hispanic.
The study says that wealthy students do have more-effective teachers on average than do poor students. But the researchers argue that the difference is too small to have a large impact on achievement. Researchers discovered, for example, that in English/language arts and math, the average teacher of a poor student is just below the 50th percentile, while the average teacher of a wealthy student is at the 51st percentile. This, say the authors, equates to nearly equitable access to effective teachers across most of the districts they studied.
In three of the 26 districts studied, however, researchers found differences in teacher effectiveness for wealthy and poor students that are significant enough to contribute to the student achievement gap in math. In these three districts alone, the researchers conclude, if both rich and poor students had equal access to effective teachers, the achievement gap would decrease significantly, by 4 percentile points or more after five years. (No meaningful inequities were found in the other districts in math or English/ language arts).
A Look at the Effects of Hiring and Mobility Patterns
The study also examined teacher hiring and mobility within the 26 districts and found small differences in access to effective teachers. Schools with a large number of poor students, for example, employ more new teachers than schools with wealthier students. But the researchers concluded this difference (11 percent of teachers in high-poverty schools are new hires compared with 5 percent in wealthier schools) is too small to have much of an effect. Besides, the researchers reasoned, new teachers’ performance improves quickly. In fact, according to the study, new hires by and large become as effective as the average teacher after one year of experience.
Teachers transferring to different schools at the end of the year don’t seem to have much of an impact on access to effective teachers either. Those who transfer from a low-poverty school to a high-poverty school are less effective than teachers who take the opposite course of action, according to the study. But the researchers conclude that such transfers should have only a small influence on inequity because only a small number of teachers, just under 2 percent, make a move to a school with higher poverty rates than the one they left.
Similarly, teacher attrition patterns do not contribute to differences in the effectiveness of teachers of rich and poor students, according to the study. Teachers who leave a district from a wealthy school and teachers who leave districts from low-income schools are both less effective than the average district teacher. The average teacher who leaves a low-income school is at the 43rd percentile, while the average teacher who leaves a high-income school is at the 46th percentile. This is not a significant enough difference to impact access to effective teachers, the researchers say.
The study concludes that both rich and poor students have a mix of effective and ineffective teachers. And even if rich and poor students were provided with an equal number of effective teachers for five years straight, the student achievement gap wouldn’t decrease substantially.
A version of this news article first appeared in the Teacher Beat blog.