Lower Income or Lower Class: What Matters for Social Mobility?

Social mobility tends to be measured using income brackets, rather than class – but money is only half the story. Richard Rothstein over at  the Economic Policy Institute argues  the achievement gap in education isn’t just about the money a person’s parents make but about other, possibly more important traits shared by those growing up disadvantaged. He writes:

“Lower class children are not only characterized by having families with low current money income; they also have a collection of interacting characteristics, each of which affects the ability to learn. … In short, the poverty rate itself is not an adequate explanatory factor. Lower class status better explains what we puzzle about.”

Rothstein’s onto something important here, and his post comes in the context of a larger conversation in the blogosphere about school reform to address gaps in achievement. Measures of social class that may be only imperfectly captured by income include things like maternal education, household stability, neighborhood quality, or aspirations for children’s schooling. Rothstein’s own research has fruitfully used the number of books in a house (or more specifically, the number of feet of shelf space devoted to books) as a benchmark of social class.

A good example of research that attempts this can be seen in the Brookings paper, “Pathways to the Middle Class”, which deliberately distinguished between “advantaged” and “disadvantaged” children, rather than just high and low income children.  Income is quite often the easiest data to analyze and will also act as good proxy for other dimensions of disadvantage. But when it comes to policies to promote mobility, we need a broader definition of disadvantage than just low income.