Family income is associated with student achievement, but careful studies show little causal connection. School factors—teacher quality, school accountability, school choice—have bigger causal impacts than family income per se.
Thinking otherwise is a group of advocates and interest groups, including leaders of the country’s two big teacher unions, that calls itself the Broader, Bolder Approach (BBA) to school reform. Its mission statement says that “weakening [the] link [between income and achievement] is the fundamental challenge facing America’s education policy makers.” In a paper given last November, Duke University Professor Helen F. Ladd, a BBA co-chair, makes the best case she can for the group’s position. She shows that in fourteen different countries student achievement is higher if a student comes from a family with higher income.
But a correlation proves nothing about cause and effect, as I explain in a new article, “Neither Broad Nor Bold,” and in an op-ed in the New York Daily News. Years ago, Susan Mayer, former dean of the Harris School at the University of Chicago, showed that much of the connection between income and achievement is spurious, caused by other factors associated with both. More recently two Brookings scholars, Julia Isaacs and Katherine Magnuson, updated the Mayer work by examining an array of family characteristics – such as race, income, mother’s and father’s education, single or two-parent family, smoking during pregnancy – on school readiness and achievement. The Brookings study found that the distinctive impact of family income was just 6.4 percent of a standard deviation, which is generally regarded as a small effect. The impact of the rise in single-parent families is likely to be much more important for student achievement than any changes in the distribution of income in the United States.
In the end, Ladd and her BBA colleagues seem to agree that income redistribution is not essential, as they quickly drop the idea in favor of an alternative dear to the heart of any public-sector union leader: Expanding the range of social services to include medical and nutritional services as well as pre-school, after-school, and summer programs. All those expensive programs outside the regular school day would undoubtedly add to the number of professionals available for recruitment by public-sector unions. But none of them hold as much promise for student learning as any one of the many school reforms on the nation’s agenda—student and school accountability, school choice, and changes in teacher recruitment, compensation and retention policies.
Jay Matthews, of the Washington Post, says it is “galling,” at least to some, for me to have worried about the rising number of single-parent families while doubting the value of hiring more professionals. But I am surprised he thought my common-sense observations were “thrilling.” I concede that adjective to Jay only if he agrees that little boys are exhilarating when speaking frankly about emperors parading in birthday suits.
– Paul Peterson