Complex causation in human behavior means that social science often isn’t very scientific. Not every variable can be measured with such accuracy as, for example, annual income and years of education, and things which are not measured tend to be neglected as factors in social science. Researchers don’t usually find correlations by accident, and they never find correlations except in measurable data, so that a certain level of inaccuracy and error is inevitable.
All of this is necessary preamble to an Atlantic Monthly article by Matthew O’Brien with this provocative headline:
Why Is the American Dream Dead in the South?
Uh, it’s not. The research O’Brien cites refers to the chance that someone whose parents are in the bottom 20% of the income distribution can rise to the top 20% of the distribution.

Stipulating that the data in the study is complete and accurate, and that everything in the analysis is legit — well, why is there a bright spot on the resulting map in the vicinity of Tuscaloosa, Alabama, but no corresponding bright spot near Athens, Georgia? Why does rural Arkansas look like a beacon of upward mobility, while the bustling economies of Atlanta and Charlotte produce no such effect?
Most of all, why does the map referenced by O’Brien show that impoverished Appalachia offers more opportunity for advancement than any of the more prosperous surrounding flatlands?
To use a social science term: Your data is obviously fucked up.
Look, O’Brien: I don’t want to start a fight, but if somebody tells you West Virginia is a glory land of economic opportunity, this is obviously somebody who never set foot in West Virginia. I don’t give a damn what they tell you after that, their credibility is shot.
With the strange mixture of credulous certainty and interventionist enthusiasm that behooves a writer for the Atlantic, however, O’Brien proceeds to draw conclusions from this research:
The researchers found that the larger the black population, the lower the upward mobility. But this isn’t actually a black-white issue. It’s a rich-poor one. Low-income whites who live in areas with more black people also have a harder time moving up the income ladder. In other words, it’s something about the places that black people live that hurts mobility.
Ri-iiiight.
Something like the poor being isolated — isolated from good jobs and good schools. See, the more black people a place has, the more divided it tends to be along racial and economic lines. The more divided it is, the more sprawl there is. And the more sprawl there is, the less higher-income people are willing to invest in things like public transit.
That leaves the poor in the ghetto, with no way out for their American Dreams. They’re stuck with bad schools, bad jobs, and bad commutes if they do manage to find better work. So it should be no surprise that the researchers found that racial segregation, income segregation, and sprawl are all strongly negatively correlated with upward mobility
So, if this is about “sprawl” that “leaves the poor in the ghetto,” why a vast expanse of low mobility in the rural South, where there are no ghettos (because there are no major cities) and where there is no suburban “sprawl” (because there are no suburbs)?
Do you see what I mean about “credulous certainty”? If you begin with the assumption that the researchers have accurately measured something meaningful — West Virginia, land of opportunity! — and then start blabbering that “the researchers found” this, that and the other correlation, you’re likely to end up making all kinds of foolish arguments, as Matthew O’Brien eagerly does:
The American Dream is alive in Denmark and Finland and Sweden. And in San Jose and Salt Lake City and Pittsburgh. But it’s dead in Atlanta and Raleigh and Charlotte. And in Indianapolis and Detroit and Jacksonville. Fixing that isn’t just about redistribution. It’s about building denser cities, so the poor aren’t so segregated. About good schools that you don’t have to live in the right (and expensive) neighborhood to attend. And about ending a destructive drug war that imprisons and blights the job prospects of far too many non-violent offenders — further shrinking the pool of “marriageable” men.
WHAT THE FUCK ARE YOU TALKING ABOUT?
You have no clue, O’Brien. “Building denser cities” in rural South Georgia? “Ending a destructive drug war” in Eutaw, Alabama? The American Dream “alive” in Pittsburgh but “dead” in Charlotte? You’re attempting to “solve” a problem you haven’t even begun to understand, and in the process making yourself a public nuisance.
UPDATE: Thanks to Eric Mertz and other commenters who looked over the Harvard study and spotted obvious issues. Here is an excerpt that clearly points toward the basic problem:
We characterize intergenerational mobility using information from de-identied federal income tax records, which provide data on the incomes of more than 40 million children and their parents between 1996 and 2012. . . . In our baseline analysis, we focus on current U.S. citizens in the 1980-1982 birth cohorts { the oldest children in our data for whom we can reliably identify parents based on information on dependent claiming. We measure these children’s income as mean total family income in 2011 and 2012, when they are approximately 30 years old. We measure their parents’ income as mean family income between 1996 and 2000, when the children are between the ages of 15 and 20.
Not to put too fine a point on it, this is insane. That is to say, what percentage of people reach the top 20% in income by age 30? Most people’s incomes peak in their 40s and 50s. Many 30-year-olds are just a few years out of college. Mertz promises a more complete analysis Monday at his blog, and we’ll wait to see what he finds. But my basic common-sense hunch — the alleged superior mobility of West Virginians — tells me something is wrong here.
UPDATE II: Welcome, Instapundit readers!