Fun With Numbers

I forgot to mention that Monday was International Dyscalculia Day, meant to achieve recognition of dyscalculia, a learning disorder related to arithmetic. I don’t have all of the symptoms, but I do have several of them. Perhaps mine is a mild case. But the truth is I do struggle with third grade-level arithmetic, and as far as I’m concerned Calculus was a Roman emperor.

So with that in mind, perhaps y’all can help me out with this — Awhile back, Paul Krugman wrote a column in which he pointed out that states governed with an anti-tax, “deficit hawk” philosophy have a pattern of providing a substandard public school education for its children. He called out Texas in particular —

The high school graduation rate, at just 61.3 percent, puts Texas 43rd out of 50 in state rankings. Nationally, the state ranks fifth in child poverty; it leads in the percentage of children without health insurance. And only 78 percent of Texas children are in excellent or very good health, significantly below the national average. The high school graduation rate, at just 61.3 percent, puts Texas 43rd out of 50 in state rankings. Nationally, the state ranks fifth in child poverty; it leads in the percentage of children without health insurance. And only 78 percent of Texas children are in excellent or very good health, significantly below the national average.

Along with this, the Economist via Scott Lemieux posted some figures showing that students from the five states that have completely eliminated teacher collective bargaining rights — South Carolina, North Carolina, Georgia, Texas, and Virginia — tend to have very below-average standardized test results. Scott withdrew these numbers, however, because he decided they were faulty, and are also based on very old data. Here is the original data, if you want to look.

Anyway, a rightie blogger, Iowahawk, called bullshit on Krugman’s column and on the figures Scott cited and then withdrew. Iowahawk argues that the reason Texas looks bad compared to Wisconsin is that Wisconsin has a much smaller percentage of racial minority students than does Texas, and if you compare student test scores by race, you see that Texas beats Wisconsin. In other words, Texas white kids outscore Wisconsin white kids, and the only reason the Wisconsin school system ranks higher than Texas’s is that Wisconsin has a much higher percentage of white kids. And yeah, there’s more than a whiff of racism here, but data is data.

Iowahawk is getting his data from the National Center for Education Statistics, a branch of the Department of Education. The center has data from the National Assessment of Educational Progress (NAEP), which appears to be a standardized test administered to 4th and 8th grade students nationwide. And I’m going to assume he is accurately representing the figures he got from NCES.

If you go to this page you can get simple graphics for each state showing how the state’s test scores compare to the national average. The states all along the southern border, including California, are below average, except for Texas, which is just exactly average. So, compared to neighboring states, Texas does pretty well. (Note — here and throughout, I’m only looking at 4th grade scores, because I’m short of time to go into this further. But I think the 4th grade scores give us a good general comparison.)

States above the Mason Dixon line tend to have above-average test scores, with a few exceptions — Oregon, Illinois, and Michigan are struggling. And note that Oregon is slightly “whiter” than Wisconsin — the racial demographics are very similar — but the most recent test scores are closer to those of Texas, around average.

I assume the southernmost states have a much higher percentage of English as a Second Language (ESL) students than the northern states, and I assume that could have some impact on standardized test scores, although I don’t know that for a fact.

My quibbles — First off, the data I would like to see, and which the NCES does not appear to provide, would compare groups by income level, not race. I postulate there is at least as strong a correlation, if not stronger, between income disparity and test disparity than you would find for race. The racial disparity you see in some states would be a reflection of the income disparity.

And repeat after me: Correlation is not proof of causation.

I suspect also that Texas has a higher percentage of what might be called the “upper income” middle class — not rich, but comfortable — compared to next door neighbor states — Louisiana, Arkansas, Oklahoma, New Mexico — all of which fare worse compared to national test results than Texas.

Texas public school spending per pupil statewide is not that high compared to other states, but I’d bet there is a big difference in per pupil spending between wealthy suburbs and the colonias along the Mexican border. And I postulate that the suburbs of Dallas and Houston have a high enough tax basis to support pretty decent public schools — about half of the money that pays for pubic schools in Texas comes from local sources, which would be property taxes and, I assume, school bonds.

(Yes, California has wealth, too, and worse test scores than Texas. But California shot itself in the foot by drastically limiting property taxes awhile back. Before Proposition 13, California had the best public schools in the nation. Now a much higher percentage of pubic school costs are paid by the state, which doesn’t help the state budget any.)

Anyway, it might be illuminating to line up data from Texas and Wisconsin that compared test results of students from families with the same level of income. I postulate you would see that Wisconsin is providing a better education to its lower-income residents, a large part of which are rural whites.

And for what it’s worth — Wisconsin has a slightly higher median household income than Texas — $52,094 to $50,043, or ranked 21 and 27, respectively, among the states. Texas has a much bigger percentage of population below the poverty level, however — 15.8% compared to Wisconsin’s 10.4%; the two states ranking 8 and 38 in poverty level. My theory is that Texas has lots of impoverished communities with substandard schools, dragging down the statewide assessment scores.

Conservatives like to claim that there’s no correlation between per pupil spending and educational results, but lets take a look at that. This chart ranks per-pupil spending per state, and there’s a big difference between the top spending state and the bottom. The guy who compiled the chart wants to make the case that spending doesn’t matter, because, he says, there’s no correlation between per pupil spending and SAT scores.

However, I’ve seen an argument that the SAT scores are not necessarily a good indicator of a school system’s performance, since not everyone takes the SAT. And, interestingly, studies have found a strong correlation between family income levels and SAT test results; the higher the family income, the higher the test scores.

I wish I had the time to line up the per-pupil spending chart with the test data from NCES, because I suspect there is at least some correlation there. The states with the highest per-pupil spending — Vermont, Wyoming, New Jersey, New York, and Maine — all have above average results, especially Vermont and New Jersey. And New Jersey has lots of those ethnic minorities that allegedly pull down scores. As I remember, some school districts in New Jersey have very high percentages of ESL students, but I don’t know how the state overall would compare to Texas.

The states with the lowest per-pupil spending — California, Texas, Nevada, Arizona, and Utah — are less impressive. Utah — a much “whiter” state than Texas, note — is around average — slightly below average in reading, just a hair above average in science and mathematics. Wikipedia says Utah is 95.20% white, so if race were such a strong factor in test scores, you’d think Utah would be above average. It ain’t.

Nevada — also a “whiter” state than Texas, although not as much as Utah — is way below average in everything.

And unrelated to income, there’s another aspect of Texas that you have to factor in, which is the infamous Texas TAKS system. The biggest reason textbook publishers for years have had to create “Texas edition” textbooks is that Texas has its own assessment system, and lessons plans and textbooks must “teach to the test.” The teacher’s editions of Texas textbooks — which I have helped to produce — are filled with standardized test directions that don’t appear in the national editions. So one would expect Texas students to have an edge with assessment tests. Whether than translates into a better overall education is a point to be debated.

Getting back to the argument of whether teacher’s unions help or hinder education — three of the the five “no arbitration whatsoever” states — South and North Carolina and Georgia — have mostly below average standardized test scores (North Carolina has above average reading scores though). Texas, as I’ve said, is average. Virginia, however, is above average. Again, one suspects median income has something to do with that — Virginia ranks eighth among all states in median household income.

So what are we learning here? First, racial demographics by themselves are no excuse for poor public schools. We can find nearly all-white states with below average schools and racially mixed states with above average schools.

I postulate there is some correlation between per-pupil spending and NAEP scores, although I don’t have time to run through all the numbers. There does appear to be a strong correlation between median household income and NAEP scores, but again, I don’t have time to work that out for every state.

And does any of this show what effect teacher’s unions have on education? I don’t think so. That’s not to say there isn’t an impact, but you can’t see it by looking at the state-level data. There are too many other variables from one state to another.