Does Zip Code Really Matter?

Huck/Konopacki Labor Cartoons

A new report from the Brookings Institution reveals a strong correlation between housing prices and school test scores. However, many are claiming a causal relationship between housing prices and school quality, something that is not supported by the data.

There is indeed a strong correlation between housing prices and test scores. The Brookings study examined state standardized test scores from 84,077 schools in 2010 and 2011 and found that the average lower-income student attended a school that scored at the 42nd percentile on state tests, while the average affluent student attended a school that scored at the 61st percentile. The largest disparity was in the northeast, where homes near high-performing schools were worth 2.4 times more than those near low-performing schools on average. Connecticut’s Bridgeport-Stamford-Norwalk region had the largest test score gap and income disparity.

However, the main cause of both high test scores and exclusionary residency is familial wealth. It should be obvious that greater wealth allows one to purchase a more expensive home in a more affluent neighborhood. So long as neighborhood schools are attended primarily by children who live near those schools, they will continue to be segregated by class.

Wealth also leads to better health outcomes because wealthier people have greater access to healthy foods, cleaner environments, comprehensive health care, and less stressful working and living conditions. This results in affluent children having significantly lower rates of chronic disease and absenteeism, which can have a significant impact on academic success. They are much less likely to be born premature or with low birth weight, suffer lead poisoning or anemia, and numerous other conditions that can impair cognitive development or cause learning disabilities.

Affluent children have many other advantages growing up that improve their educational outcomes. For example, they have substantially larger vocabularies and pre-literacy skills before they have even entered kindergarten (see here and here) because they hear a greater variety of words at home as they grow up. They are also more likely to have enriching extracurricular opportunities like summer camps, travel, private arts and music classes, and they are more likely to have access to tutors, personal computers and educational toys and games growing up.

Of course affluent schools also tend to receive substantially more in donations from parents and community members than lower income schools, allowing them to retain arts programs, athletics and librarians. But the main reason for their higher test scores are the numerous life advantages their affluent students have enjoyed since the time they were still in the womb.

The report suggests that ending exclusionary zoning practices would significantly reduce the test score gap by making schools less segregated by social class. Desegregation of the schools might help raise test scores for some lower income students, particularly those who already have sufficient academic skills, motivation and familial support. But students who are far behind in credits and reading and math skills will need far more than the inspiration of being surrounded by higher achieving students or access to a librarian to bring them up to speed. There is nothing intrinsically better about affluent schools that would cause low performing students to suddenly excel.

If all schools were fully desegregated by class, with equal numbers of affluent and poor children, it is indeed likely that the gap in test scores between schools would decline. This is because the scores in the once predominantly affluent schools would likely decline with the influx of lower performing students while the scores in the hitherto lower income schools would rise with the influx of affluent children. However, desegregation should not have any significant effect on the test score gap between students of different socioeconomic backgrounds since their social class and life experiences would remain more or less unchanged.

Huck/Konopacki Labor Cartoons

 It is also hard to imagine a scenario in which affluent parents would allow their privileged schools to be diluted with rabble from the other side of the tracks. These are the parents with the most political clout and the money to back it. They resist spreading parental donations equally throughout their school districts. They resist changing school funding rules to ensure that districts with lower property tax bases receive the same resources as their districts. They like their high test scores, Advanced Placement courses, arts electives and trouble-free campuses.

Yet if push came to shove and social class desegregation was imposed on them by the courts, they have the resources to transfer their children to elite private schools and many would likely do so.