But first, some background:
According to the U.S. Census Bureau’s American Community Survey, the population of U.S. 18- through 24-year-olds not enrolled in school and without a high school diploma or General Educational Development, or GED, credential was 16.4 percent in 2009. Among 16- to 24-year-olds who were incarcerated during 2006-07, only 1 in 1,000 had a bachelor’s degree, while 6.3 percent were high school dropouts who didn’t have a GED. (Sum, Khatiwada, McLaughlin & Palma, 2009).
As to Virginia, here are the division average, on-time diploma rates for economically disadvantaged students (“ED”) plotted v. the rates of their more affluent peers (“Not ED”) (data are percentages).
Richmond’s disastrous performance aside, these data share with the dropout data a curious inversion: Given that ED students generally underperform their Not ED peers on the SOL tests (for example, see here), we might expect that the ED graduation rates would be lower than the Not ED. The state averages, ED 87.2 & Not ED 93.9 are consistent with that. But Richmond shows a higher ED than not ED rate, 73.9 v. 65.9. And the fitted line, notwithstanding the relatively low R-squared value, suggests that on average Not ED rates below 84.6 are associated with higher ED than Not ED graduation rates.
Indeed, all the divisions above the gray line on the graph below exhibit that anomaly.
Trophy Offer: As with the dropout data, I’ll give a #2 lead pencil as a prize to anybody who can offer a (testable) hypothesis that explains this phenomenon. But before you heat your brain up on this, take a look at the post that will follow this one in a day or two.
Turning to the data by school, we see the details of Richmond’s win in the race to the bottom.
As well, the Richmond schools, other than Marshall and the three selective schools, show anomalously high ED graduation rates.
Of course, Richmond’s graduation rates are a direct reflection of the dropout rates.
The red diamonds are the peers, from the left Newport News, Hampton, and Norfolk.