Is Marriage Good for Schools?

Having been enticed by the 2017 census data, I turned from the “female householder, no husband present” data to the “married couple families” numbers.

Notes: The census table does not include data for the two towns that have independent school divisions, Colonial Beach and West Point.  Presumably those data are included in the reports for the surrounding counties; I don’t have a way to correct for that (other than by leaving out the counties, which I didn’t do).  VDOE reports consolidated SOL data for Emporia/Greensville County, Fairfax City/County, and Williamsburg/James City County under the latter jurisdiction in each case; I’ve summed the census data for each pair and reported the joint average.

Let’s start with reading.

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Not only did we get a two-digit R-squared, for a change, but one that is robust: Division reading SOL pass rates are strongly associated here (ρ = +0.68) with the percentage of married couple families.

Of course, the correlation does not tell us about causation.  Indeed, it is likely that other factors drive both sets of numbers. 

That caveat aside, we again see Richmond (the gold square) underperforming substantially while the peer jurisdictions (the red diamonds, from the left Norfolk, Newport News, and Hampton) are near or above the fitted line.  (As a courtesy to both of my readers, the purple diamond is Lynchburg, the green, Charles City.)

For a closer look at Richmond’s marital neighborhood, here is the same graph, expanded to show only the jurisdictions with <65% married couples.

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The fitted line is for the entire dataset.

The math scores tell the same story (with Richmond underperforming even more dramatically).

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As with the “female householder” dataset, the married couple SOL data also show suggestive correlations with both the economically disadvantaged (“ED”) and the more affluent (“Not ED”) students’ performance.

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(In the second graph of each pair, only the ED points are labeled.  Look directly above those points – same % married – to find the corresponding Not ED points.)

Indeed, the fits to the Not ED group are substantially more robust than to the ED students, showing where marriage or the underlying factors that affect both marriage rates and SOL pass rates has/have stronger effects.

As in the single parent case, these data tell us:

  1. The raw SOL pass rates punish a division for poverty and even more for families without married couples; and
  2. Even with the pass rates corrected for the effects of both larger populations of ED students and lower populations of married couples, the Richmond schools underperform.  Appallingly.