Why Do the Achievement Gaps Exist?
School desegregation was meant in part to reduce the racial gap in achievement. However, research has found inconsistent effects of racial composition on academic performance. A study of Texas schools aims to set the record straight.
This reports some of the ideas and findings from the following source:
Hanushek, E. A., Kain, J. F., & Rivkin, S. G. (2002).New evidence about Brown v. Board of Education: The complex effects of school racial composition on achievement.National Bureau of Economic Research, Working Paper 8741. Pp. 1-9, 29-30
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Did school desegregation have the desired effects? Nearly 50 years afterBrown v. Board of Education(1954), blacks are more likely to have white classmates, yet blacks still lag behind whites on achievement test scores. Researchers Eric A. Hanushek, John F. Kain, and Steven G. Rivkin look at the effect of desegregation in Texas schools on the racial gap in achievement.
Like other areas of the country, desegregation in Texas did not lead to perfect integration because of a rise in housing segregation and district constraints on enrollment. The authors say that a general fall in white enrollment in Texas public schools between 1968 and 1998 was offset by a rise in Hispanic students (see Figure 1).
Despite the relative decline in white enrollment, the average percentage of blacks' schoolmates who were white rose from 24% to 35% between 1968 and 1980 (and then fell to 31% by 1998). Given the state's agricultural heritage, growing suburban communities often encompassed significant numbers of blacks. The authors say this negated some of the effect of white flight and led to a relatively high percentage of blacks (50%) attending schools where the student body is largely non-black (67%).
Although blacks have more white classmates than they did in 1954, black third graders in Texas still have not caught up to whites in terms of achievement test scores (see Figure 2). The authors want to know if current levels of segregation are partly to blame.
Studies of the short-run outcomes of forced desegregation show "mixed effects" on "achievement, self-esteem, and racial attitudes" (p. 6). However, Hanushek and his colleagues say that most of these studies have biased samples and do not control for the conflict and resistance that characterized the early stages of desegregation.
A related strand of research looks at the effects of racial composition (peer effects) on student outcomes. Several studies have found that "racial isolation harms academic achievement" (p. 7), although the authors say that it is hard to tell whether racial composition simply is a "proxy" for differences in "school quality or other omitted factors" (p. 7). Other studies have found little or no evidence linking racial segregation to academic achievement.
Hanushek and his coauthors say that research needs better ways of defining and especially measuring important peer characteristics. Some studies control for socioeconomic and academic background, but few take family preferences for residence or education into account. Such preferences may affect both academic achievement and the racial composition of schools.
The authors say that their research on Texas schools pays special attention to family factors and school quality since these may otherwise show up as a peer effect on achievement. After controlling for these variables, they find that a higher percentage of black schoolmates lowers the achievement of blacks with above-average abilities. However, racial composition has little effect on lower ability blacks, whites, and Hispanics.
"While any interpretation would be speculative," the authors write, "the results are consistent with the views that blacks impose peer pressure on other blacks not to achieve and that a higher proportion of blacks may lead teachers to reduce their expectations for all blacks" (p. 28).
Since further desegregation is limited by district boundaries, Hanushek and his coauthors conclude that the best way to narrow the achievement gap may be the continued suburbanization of black Americans through, for example, housing dispersal programs such as Gautreaux.
This study measures peer influence on student achievement by looking at changes in the racial composition and test scores in Texas schools.
A matched panel data set of school operations constructed by the UTD Texas Schools Project was used for the analysis. This data set tracks three successive cohorts of students, with the first beginning third grade in 1992. The authors use data for grades 4&6 for one cohort and grades 4&7 for the other two. They exclude the relatively small numbers of Asian and Native American students from their sample.
The authors use a value-added model of achievement, where changes in a student's test scores(standardized mathematics results from the Texas Assessment of Academic Skills) from one grade to the next is a function of:
Using a value-added model circumvents the problem of omitted historical variables, the authors say, since only two observations on each student are required.
However, problems with measuring school quality, individual ability, and neighborhood and school choice by parents remain. Each of these can show up as peer influence if left uncontrolled. The authors attempt to eliminate this potential bias by breaking the error term of their model into time invariant:
These "fixed effects account for the primary systematic but unobserved differences in students and schools," the authors write (p. 13). A potential correlate of racial composition that remains is family relocation in response to anticipated problems. However, the authors say that such costly decisions should lag behind changes in peer, teacher, or school characteristics.
This study was supported by the Spencer Foundation, the Mellon Foundation, the Smith Richardson Foundation, and the Packard Humanities Institute.
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