Because of the fact that whites and Hispanics together make up a much greater share of the population than blacks, the scores of the "low income" group are drawn primarily from the scores of white and Hispanic children whose families are making between $15,000 and $30,000, and this leads to the impression that the lower scores of blacks are not adequately accounted for by their low income, when in fact the question of income has not been adequately addressed by the data collection and analysis methods.
Race differences in SAT scores are are large even when accounting for income.
http://www.jbhe.com/features/49_college_admissions-test.htmlThe Widening Racial Scoring Gap on the SAT College Admissions Test
Journal of Blacks in Higher Education
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There are a number of reasons that are being advanced to explain the continuing and growing black-white SAT scoring gap. Sharp differences in family incomes are a major factor. Always there has been a direct correlation between family income and SAT scores. For both blacks and whites, as income goes up, so do test scores. In 2005, 28 percent of all black SAT test takers were from families with annual incomes below $20,000. Only 5 percent of white test takers were from families with incomes below $20,000. At the other extreme, 7 percent of all black test takers were from families with incomes of more than $100,000. The comparable figure for white test takers is 27 percent.
But there is a major flaw in the thesis that income differences explain the racial gap. Consider these three observable facts from The College Board's 2005 data on the SAT:
• Whites from families with incomes of less than $10,000 had a mean SAT score of 993. This is 129 points higher than the national mean for all blacks.
• Whites from families with incomes below $10,000 had a mean SAT test score that was 61 points higher than blacks whose families had incomes of between $80,000 and $100,000.
• Blacks from families with incomes of more than $100,000 had a mean SAT score that was 85 points below the mean score for whites from all income levels, 139 points below the mean score of whites from families at the same income level, and 10 points below the average score of white students from families whose income was less than $10,000.
