RALEIGH – Well, that clarifies matters.

In a Sunday package, reporters from the Charlotte Observer and Raleigh News & Observer worked together to explore the controversial subject of school assignment. The two largest school systems in the state, Wake and Charlotte-Mecklenburg, have chosen differing policies in response to federal litigation striking down race-based school assignments.

Wake preserved forced busing by substituting household income for race, hoping to enhance student performance by avoiding high concentrations of low-income students. CMS adopted voluntary busing based on neighborhood zones and choice options, directing additional resources to schools with high at-risk populations.

In the CO/N&O piece and subsequent commentary, partisans of the Wake policy continued to assert their case. But it was akin to standing in the back of a theater and waving one’s arms wildly in an attempt to distract the audience from the drama on stage. The real story lay in the numbers, and they clearly did not support the forced-busing argument.

Simple comparisons of average test scores from Wake and CMS won’t suffice. While the two systems are nearly equal in total enrollment, the composition of the enrollment is markedly different. In Wake, fewer than 30 percent of students are eligible for free or reduced-price lunch, the standard proxy for disadvantage. In CMS, nearly half the students are.

So meaningful conclusions can be drawn only after performance on state tests is broken out by such factors as race and socioeconomic status. The result? “Despite the different approaches,” writes reporter Keung Hui, “the academic results among minority and at-risk students are very similar in both districts, with only a narrow gap in test scores.” Indeed, the gap is insignificant given the fuzziness of the underlying data the newspapers reported. About 46 percent of Wake’s lower-income students passed either the reading or math exam last year, vs. 45 percent of lower-income students in CMS. The statewide average for these students was 48 percent.

I went straight to the data source, from the Department of Public Instruction, and further narrowed the focus to the share of disadvantaged students passing both the reading and math tests. In CMS, that rate was 31 percent in 2007-08. In Wake, it was also 31 percent. For the state as a whole, it was 33 percent. As for bragging rights, urban school systems outperforming both Wake and CMS among lower-income kids included Cumberland (33 percent), New Hanover (34 percent), Chapel Hill/Carrboro (34 percent), Asheville City (38 percent), and Buncombe (44 percent).

(By the way, CJO readers may remember my recent column about Charter Day School in Brunswick County. Its passing percentage was 51 percent of its lower-income students.)

There’s little more that needs to be said – not that some busing advocates haven’t been huffing and puffing anyway, trying to blow this statistical house down. But it’s made of bricks, not straw or sticks. Wake boosters like to count up the number of schools that met or exceeded achievement or growth standards, for example. Given the similar performance when the scores are disaggregated by income, however, school-based counts are actually just a measurement of the extent of Wake’s forced-busing policy. They aren’t a proper measurement for comparing student achievement in the two systems. In short, there appears to be no valid statistical case at the moment for the proposition that Wake’s social engineering improves student performance.

Admittedly, there would be another way to test the proposition. Rather than rely on system-wide averages, we could track the performance of individual students as they are transferred into schools under Wake’s assignment scheme, to see how the transfers affect their individual performance on state tests.

But that is precisely the study that Wake school officials have refused to perform. Wonder why?

Hood is president of the John Locke Foundation