In 1954, the Supreme Court ruled that state-mandated racial segregation in schools was unconstitutional. But the desegregation of Southern schools was delayed by state and local resistance. It was not until the late 1960s, when the federal government and the courts began to enforce the Brown v. Board of Education decision, that desegregation began in earnest. This process resulted in both short- and long-term benefits for Black students. Recent research clearly shows that desegregation raised Black students' high school and college attendance and graduation rates, increased Black students' wages as adults, lowered their incarceration rates, and improved their health (Anstreicher, Fletcher, & Thompson, 2022; Ashenfelter, Collins, & Yoon, 2006; Guryan, 2004; Johnson, 2019). This was because desegregation offered Black students access to better-resourced schools, with smaller class sizes and more funding (Johnson, 2019; Lafortune, Rothstein, & Schanzenbach, 2018).
Despite these substantial benefits, the desegregation movement of the late 1960s and early 1970s did not last. Most school districts largely abandoned serious and intentional efforts to continue integrating schools after the mid-1970s. As a result, our public schools remain highly segregated by race and income today, although they are less segregated than they were 60 years ago. Moreover, both the racial and economic segregation of schools have increased in the last 30 years. Today the average Black student in a large school district attends a school with 32 percent more Black and Hispanic students than the school the average white student attends; in 1991 the comparable number was 24 percent. Segregation by poverty has grown even faster. In 1991, the average free lunch-eligible student attended a school with a 14 percent higher poverty rate than schools attended by the average non-eligible student in the same district. By 2020, that figure had increased to 21 percentage points (Owens et al., 2022).
Tracing Segregation
While today's schools are still less segregated than in the 1960s, persistent and rising segregation—and the lack of coordinated efforts by districts, states, and the federal government to reduce it—is cause for concern. By not addressing racial and economic segregation and focusing narrowly on "school reform" and "school improvement," the country has implicitly retreated from the Brown v. Board ruling that segregation is inherently harmful and replaced it with the belief that it's possible to have equally high-quality schools in every neighborhood—even if that means school systems are segregated. It's worth asking whether that is a fair assumption. Does segregation have the same harmful effects today as it did 60 years ago? And if so, why? Over the last few years, we have been working to answer these questions (reardon et al., 2022).
We first collected data on school enrollment patterns and academic achievement from the 2008–09 school year through the 2018–19 school year in every district—over 13,000—in the country. By looking at the enrollment and achievement patterns in each district separately by race and poverty status, we were able to construct measures of racial and economic school segregation and racial and economic disparities in achievement in each district in each of those years. This massive dataset (publicly available at https://edopportunity.org)—containing data reflecting the experiences of over 50 million students enrolled in public schools in the last decade—can teach us a lot about patterns of educational opportunity and their consequences for students.
The achievement disparities between racial groups (sometimes called "achievement gaps") are signals that students have experienced very different levels of educational opportunity. That is, racial "achievement gaps" are symptoms of racial "opportunity gaps"—systematic differences in access to the kinds of experiences that help children develop academic skills. Thus, when we see a large white-Black achievement disparity in a school district, it tells us that Black students in that district have grown up with far fewer educational opportunities than their white classmates. The differences in opportunities may occur because their families have different incomes and socioeconomic resources, because they live in neighborhoods with different resources, or because they attend K–12 schools of different quality and have different opportunities in their schools.
One of the important features of these data is that they allow us to measure how achievement disparities grow or narrow as children progress through grades 3–8. And by examining the characteristics of school districts where racial and economic achievement disparities narrow the fastest, we can learn something about the schooling conditions that lead to more equitable opportunities for Black, Hispanic, and low-income students. Here are four key findings from these data:
Finding 1: Achievement disparities are generally larger in more segregated school districts.
On average, school districts with higher levels of racial or economic segregation also have larger white-Black, white-Hispanic, and nonpoor-poor achievement disparities (reardon, Kalogrides, & Shores, 2019; reardon et al., 2022). In the average large school district, white students are achieving two grade levels above Black students, indicating that white students have had far greater opportunities throughout their lives than Black students. This difference in academic performance is as much as five grade levels in some communities. Notably, the achievement disparities are larger, on average, in more racially segregated school districts. These patterns are the same when we look at white-Hispanic or nonpoor-poor achievement disparities and segregation.
This finding suggests that segregated schools are the cause of achievement gaps, but one should be careful before drawing that conclusion. Some of the same factors that lead to high levels of school segregation might also lead to large achievement disparities. In places where nonpoor and poor families or white and minority families have very different average incomes—Atlanta or Washington, D.C., for example—white and minority children grow up, on average, in homes and neighborhoods with different levels of economic resources and attend preschool programs of very different quality. These different experiences can result in large achievement disparities, even apart from the effects of school segregation. In short, we cannot immediately tell from these data whether the gaps are large in places like Atlanta and Washington, D.C., because of differences in families' economic resources or because of school segregation.
Interestingly, however, even in districts with high levels of racial segregation—like Washington, D.C., New York City, and Detroit—the achievement gaps vary widely. The achievement gap is near zero in Detroit and over five grade levels in Washington, D.C., despite their similar levels of racial segregation. This indicates that some other factors beyond racial segregation must be contributing to the size of achievement gaps. Put another way, the data show that although racial segregation is clearly linked to achievement gaps, it is not the sole factor that influences them.
Finding 2: Achievement gaps generally grow faster in more segregated school districts.
To better understand whether—and how—school segregation leads to unequal educational opportunity, it is useful to look at the association between segregation and the growth of achievement gaps during K–12 schooling (see Figure 1). This is a better test of whether school segregation itself affects achievement disparities because school segregation can only contribute to achievement gaps during the schooling years, not before. If school segregation led to unequal opportunity, we would expect to see achievement disparities grow as children progress through elementary and middle school. This is indeed what we see.
Source: reardon et al. (2022). The Stanford Education Data Archive. Copyright © sean f. reardon. Used with permission.
An interactive version of this figure can be found at: https://bit.ly/3zfBnGW.
Figure 1 displays the rate of change of achievement disparities in each district against its racial segregation level. There is a clear pattern: Achievement disparities grow fastest, on average, in more segregated school districts. In the most segregated school districts, the white-Black achievement gap grows by roughly one-eighth of a grade level each year. By 8th grade, the gap is more than a grade level wider than when children enter school. This pattern holds even when we compare school districts that are similar in terms of the socioeconomic characteristics of children's families, the levels of local residential segregation, and other characteristics of schools. Even within a district, the achievement gap widens more in grades and years when students are more segregated. The evidence clearly shows that racial school segregation yields unequal learning opportunities and widens achievement disparities.
Finding 3: Racial segregation concentrates Black and Hispanic students in high-poverty schools.
Does racial segregation lead to unequal opportunity because Black and Hispanic students are concentrated in schools that enroll mostly Black and Hispanic students? Or because they are concentrated in high-poverty schools? In examining these questions, we found that it is in fact the economic dimension of segregation, not the racial dimension, that leads to unequal educational opportunity. When Black, Hispanic, and low-income students are concentrated in schools with higher poverty than those that their white and nonpoor peers attend, achievement gaps grow faster. This is evident from Figure 2, which shows how the growth rate of the white-Black achievement gap is related to white-Black economic segregation (the difference in the percentage of poor students in the average Black and white students' schools).
Source: reardon et al. (2022). The Stanford Education Data Archive. Copyright © sean f. reardon. Used with permission.
An interactive version of this figure can be found at: https://bit.ly/3zfBnGW.
Figure 2 shows that when Black students within a district attend schools with more poverty than those of their white peers, achievement gaps widen. And the more time students spend in these economically segregated conditions, the more the gaps widen. This figure also helps us understand why achievement gaps grow so much faster in Washington, D.C., and Atlanta than in New York City, Philadelphia, and Detroit: Atlanta and D.C. are much more economically segregated than the other districts.
We also found that in districts where economic segregation decreased between 2009 and 2019, achievement gaps also narrowed (Matheny et al., forthcoming). In other words, the evidence is clear: When students are segregated economically, the Black, Hispanic, and low-income students who are concentrated in high-poverty schools have fewer opportunities to learn.
Finding 4: High-poverty schools appear to be generally less effective partly because they have fewer of the resources, like skilled and experienced teachers, that make schools most effective.
When we examine data from every public school in the country, we find a clear pattern: Students learn less in typical high-poverty schools than in typical low-poverty schools. This is true even when we compare students of similar economic backgrounds. That doesn't mean that every high-poverty school is less effective than every low-poverty school, but most are. Why is this? Why are we unable to ensure that all schools are equally effective, regardless of what students they enroll?
Segregation and educational inequality are not the result of a set of 'failing' schools; they are a failure of our society to live up to its ideals.
One reason is staff turnover. Schools enrolling high proportions of low-income students often have high rates of principal and teacher turnover, and so tend to have more novice and uncertified teachers and higher rates of teacher absenteeism. Part of the reason why segregation leads to widening achievement disparities, therefore, is that it concentrates Black, Hispanic, and low-income students in high-poverty schools that have fewer experienced and effective teachers (Darling-Hammond, 2004; Peske & Haycock, 2006). In our research, we find that the inequitable distribution of skilled teachers among schools accounts for one-fifth of the effect of segregation on achievement disparities (reardon et al., 2022).
But there are several additional reasons why achievement disparities tend to grow faster in segregated school districts. Schools with high concentrations of low-income students are often provided with too few resources to adequately meet the needs of their students; they offer fewer advanced courses; and their students' parents have fewer political, social, and economic resources (Kucsera, Siegel-Hawley, & Orfield, 2015; Murray et al., 2019). Without a critical mass of economically advantaged students, high-poverty schools face an uphill battle in obtaining the resources they need to support their students.
What Do We Do Next?
Solving the problem of inequity in education will require a concerted effort at all levels of the system—schools, districts, states, and the federal government. But one thing is clear from the accumulated research: When we allow our schools to remain segregated by race and economic status, we are systematically providing fewer educational opportunities to our most vulnerable students. That does not mean segregation is the sole cause of educational disparities, but it magnifies them.
Reducing segregation is not simple, but it is possible. School districts have considerable control over student assignment practices. They can and should do more to ensure that Black, Hispanic, and low-income students are not disproportionately concentrated in high-poverty schools. They can choose where to locate new schools; how to draw attendance zone boundaries; and which students to give priority in school choice policies. Many districts are experimenting with such policies, and we still have much to learn about what strategies are most effective. Districts can also work with housing authorities to change patterns of residential segregation through strategic use of housing vouchers and decisions about where to locate low- and mixed-income housing developments.
It is not the racial dimension of segregation that impacts student achievement; rather it is the economic dimension of segregation that leads to unequal educational opportunity.
But we can do more than this. State and district leaders can gather data to better understand how they distribute teachers, staff, and other resources among their schools. For two decades, education policies have been designed to hold individual teachers, principals, or schools accountable for the performance of their students. But segregation and educational inequality are not the result of a set of "failing" schools; they are a cause of failing schools, and they amount to the failure of our society to live up to its ideals. When we see a disparity—when segregation is high, or when low-income or minority students are disproportionately in classrooms with uncertified or novice teachers—state, district, and school leaders must step in to remedy that disparity, collaborating to redistribute resources that will help ensure equitable access to effective teaching, rigorous courses, and other student supports.
We cannot fix what we do not attend to. Only by acknowledging the systemic inequities associated with school segregation and concentrated poverty can we begin to change them.
