Steady Gains and Stalled Progress: Inequality and the Black-White Test Score Gap

Chapter 3. Income Inequality and Racial Gaps in Test Scores

110 Chapter 3 Income Inequality and Racial Gaps in Test Scores MARY E. CAMPBELL, ROBERT HAVEMAN, TINA WILDHAGEN, AND BARBARA L. WOLFE I ncome inequality among American families has grown steadily since the 1980s, as has the racial-ethnic income gap (Lichter and Eggebeen 1993). These trends are documented in table 3.1, which shows that the standard deviation of U.S. family income doubled from the 1980 to 2000 decennial censuses, and that the gaps between racial-ethnic groups also rose during this period. For example, the family income gap between blacks and whites rose by more than 50 percent over these two decades, and that between Latinos and whites almost doubled. Simultaneously, urban economic segregation grew, with particularly dramatic growth among African Americans and Latinos; the poor and the rich became increasingly isolated geographically (Jargowsky 1996). Could this growth in income inequality, together with social factors related to the development, contribute to our understanding of trends in the black-white test score gap, and in particular the failure of this gap to narrow during the late 1980s and 1990s? In this chapter, we focus on the potential impact of changes in the level and distribution of family income and the larger context within which adolescents and young adults learn. Family income is a powerful predictor of educational attainment, especially college attendance (Belley and Lochner 2007; Campbell et al. 2005). Although estimates of the impact of family income on test scores vary depending on the dataset used and the standardized test score analyzed , the results consistently show a small but statistically significant effect (see, for example, Phillips et al. 1998; Brooks-Gunn, Klebanov, and Duncan 1996). This literature implies that changes in income inequality between black and white families may also explain trends in the racial gap in test scores (Phillips et al. 1998). We build on this insight and study the relationship between the growth in the income advantage of white children relative to black and Latino children and recent trends in the test score gap. Could this factor suggest why the gap has failed to narrow in recent years? Racial and Ethnic Gaps in Test Scores As we have noted, racial gaps in adolescent test scores declined significantly in the 1980s, but this progress stalled in the 1990s. Interestingly, the racial and ethnic gaps did not narrow consistently across the distribution of test scores. Although blacks and whites became more equal at the bottom and middle of the distribution, there was little improvement in the racial gap at the top for several types of standardized tests (Hedges and Nowell 1999). Significant test score gaps between Latinos and non-Latino whites also exist, and they too narrowed during the 1980s. Like blacks, Latinos are underrepresented at the top of the distribution. For example, “20% of whites, 3% of blacks [and] 7% of Mexican Americans . . . scored above a 600 on the SAT math section. . . . Eight percent of whites . . . 2% of blacks [and] 3% of Mexican Americans . . . scored above 600 on the SAT verbal section in 1990” (Kao and Thompson 2003, 421). These patterns have troubling implications in terms of future opportunities available to minorities , given that returns to standardized test scores are nonlinear, with greater rewards at the top of the distribution (Hedges and Nowell 1999). The Effect of Income on Test Scores A primary explanation for the narrowing of the black-white test score gap during the 1970s and 1980s focuses on changes in material deprivation and family characteristics over these decades. According to this argument , black parents’ socioeconomic gains relative to whites since the 1970s account for much of the narrowing of the gap by increasing the relative scores of black students (see, for example, Armor 1992). For instance, the percentages of black parents who completed high school increased dramatically from 1974 to 1999 (Hoffman, Llagas, and Snyder 2003). Variation in parental education, income, and poverty status have been found to explain between 25 and 50 percent of the variation in the black-white test score gap (Brooks-Gunn, Klebanov, and Duncan 1996; Cook and Evans 2000; Grissmer, Flanagan, and Williamson 1998; Hedges and Nowell 1998); other research has indicated that convergence in socioeconomic status accounted for a large portion of the reduction in the gaps observed in the 1980s (Hedges and Nowell 1998). Overall, most of the studies of the effects of income on vocabulary and reading test scores have suggested that the effect is statistically significant but often small (Blau 1999; Hill and O’Neill...