Mike the Mad Biologist

Do Parents Choose Schools or Student Bodies?

One of the things often heard is that someone is leaving the city for the burbs because the schools are better (I use the generic city, since, in my experience this attitude doesn’t appear to be limited to any particular city). But what if parents aren’t choosing better schools, but better student bodies? What if parents are paying exorbitant housing costs, not because the schools perform better, but because those high housing costs are able to exclude students who perform poorly?

A while ago, I wrote that, despite the best efforts of the doom-and-gloom educational assessment industry, some U.S. states actually fare extremely well when compared to other countries: Massachusetts, Minnesota, New Hampshire, and New Jersey, for instance, blow away every single European country by a large margin. What do the good states have in common? Well:

But it’s no accident that the states which do well typically have low childhood poverty rates, decent incomes, and lower divorce rates–all signs of stable families which are conducive to learning.

So I don’t know whether to be optimistic about this or not. Yglesias argues that other states can learn from MA and other high performing states. But I wonder if the real lesson to be learned is that the ‘extra-educational’ environment–what students walk into the school with–plays a really big role.

Below I’ve plotted the NAEP math scores for fourth graders against child poverty rate for 2009 (actually, I’ve used 1 – the percentage of children in poverty; data are from here and here):

parentsorschools1

For the statistically minded, R2 = 0.48, which, for an uncontrolled experiment, is pretty good (R2 is an indication of the strength of the relationship and can range between 0 – 1). For purposes of this blog post (not journal article, not policy paper, but a fucking blog post), what I want to draw attention to is that we can estimate NAEP test scores based on the child poverty rate.

For example, a population with fifty percent of children below the poverty line (which tragically is the case in some areas) will have, a score of 209 with a 95% probability of being between 197 – 219*. A population with only two percent of its children in poverty should have a score of 254 with a 95% probability of being between 231 – 274.

This isn’t to say that individual students can’t over- or underperform. And population (states or schools) can defy expectations: at the state level, Massachusetts scores twelve points higher than it should. Demography may not be destiny, but it is a heavy burden.

In the above example, there is virtually no way the poor population will ever appear as ‘good’ as the wealthy school, even if the poor school does a better job of educating its students–that is, getting them to achieve more than they should based on their socioeconomic status. Even if you compare a school with a ten percent poverty rate (half the national average) to a school with a two percent poverty rate, only a quarter of the time will the ‘poorer’ school perform better.

The point is when parents are choosing schools based on test scores, they are not necessarily assessing school quality, but child poverty. The educational system that they’re leaving might stink too, but there is a massive conflation going on here. Even if they don’t think they’re doing so, families who are moving in order to secure a better education are, to a considerable extent, fleeing ‘undesirable’ student bodies.

*We can estimate the variation in the slope as well as the Y-intercept. For purposes of this fucking blog post, I’m assuming the Y-intercept is constant. You get what you pay for.

Comments

  1. #1 jay
    December 21, 2009

    There is a body of research that suggests that peers are as important or more important a factor in children’s development than their parents.

    This falls right in line with that concept.

  2. #2 D. C. Sessions
    December 21, 2009

    There is a body of research that suggests that peers are as important or more important a factor in children’s development than their parents.

    From conversations with my colleagues who grew up in India and China, the environmental comparison is mind-blowing. Imagine a society where instilling good study habits is a parent’s #1 priority right after keeping everyone fed and housed. Imagine a society where the school social hierarchy tops out with the best students.

    Then have a look around in the USA.

  3. #3 llewelly
    December 21, 2009

    It’s really too bad you don’t have county-by-county data to make your graph with. Then you’d have at least a few areas with populations with fifty percent of children below the poverty line.

  4. #4 IP freeley
    December 21, 2009

    Yes, it is very clear that income and family stability play a huge role in how successful students are. But why not move to the burbs for a better education? If I had two identical students and put one in an inner city school where all her peers are low-scoring students and the other student in the burbs where she is surrounded by high-scorers, which one will do better?

    After family, peers are the biggest influence on young people. By moving to the burbs you increase the odds of getting high performing peers. Sure, this is maybe a second order effect, but still seems like a win if you can afford it.

  5. #5 DNLee
    December 21, 2009

    Since my time as a NSF GK-12 Fellow and reading a phenomemonal book: Supplementary Education: The Hidden Curriculum of High Academic Achievement by Gordon, Edmund W., Ed.; Bridglall, Beatrice L., Ed.; Meroe, Aundra Saa, Ed. I have truly believed that the “extra-educational environment” is what really makes the differences.

    To your point of choosing better student bodies, in poor urban areas, parents are doing just that. Especially at the middle & high school level students are constantly distracted from learning because of disruptive behavior, rudeness, and violence. I worked at a high school reknown for violence that there were 2 lockdowns and a mass gang fight. Parents who can send their kids elsewhere do so.

    The other thing about home that matters is how much education is valued. Just finishing school is not the same as valuing education and comprehending how that gives you options in life. Yeah, getting a high school diploma is often touted as an important accomplishment. But that is different than having a family that expects you to learn and understand your lessons, expects (and helps) you get assignments done and turned in on time, backs up teachers when they say you need to do more work, or finds you resources to get ahead and stay ahead over breaks.

  6. #6 JYB
    December 21, 2009

    There’s also the issue that most of these standardized tests are instructionally insensitive. They measure what the kids came in with rather than what they were taught.

  7. #7 joemac53
    December 21, 2009

    As a 34-year veteran high school math/science teacher in MA I have heard about the “achievement gap” for several years. Many teachers of my generation agree with Mike’s conclusions. Frustration with the MCAS (required for graduation) testing is not that kids or schools should not be accountable, but that the test results can be predicted by zip code.

    One funny, but expected, result of No Child Left Behind is that several schools in MA have failed to make Adequate Yearly Progress because their scores were already so high there was nowhere to go but down.

    Stability at home ranks #1, then peer acceptance, then actual teaching is what causes the high scores (or lack thereof).

  8. #8 Miss Cellania
    December 21, 2009

    The student body makes a difference in how well your child will be taught. Two equally talented teachers in different schools will have vastly different experiences. In a school with lots of poorly-prepared students, the teacher must spent an inordinate amount of time bringing the lowest-performing students up to speed. All the talent in the world can’t make up for the drain on his/her time and energy, and the other students pay for it in lost class time and individual attention.

    My children get horrible grades at a tiny parochial school. Two out of three are at the bottom of their classes (mind you, there are only 8-10 kids in each class). Their work would earn them As in the local public school, but they would learn less overall.

  9. #9 JYB
    December 21, 2009

    @2

    A good counterpoint to that is this book. Written by an Michigan State professor from China. Basically, China is trying to become more like the US in terms of education.

  10. #10 Troublesome Frog
    December 24, 2009

    This is exactly why my sister was pulled out of public school and put into one of the local private schools. I did just fine as I was hanging around with the AP crowd, taking good classes, and developing in an environment where achievement was a good thing. She wasn’t, and she was just scraping by without any serious motivation. Her friends didn’t care about school and didn’t respect people who did. The classes she was in wasted energy keeping those friends from derailing everybody else.

    Once she hit a private school where academic achievement was respected at all levels and even the “worst” students were fairly solid and expected to work hard, her output increased dramatically. I’m sure that the shiny lab equipment and new books weren’t a hindrance, but it seemed obvious to me that the major difference was who she was spending her time with and what the culture demanded from her.

    It’s really amazing what the average kid will do when you just change the definition of “average.”

  11. #11 phoenixflash
    January 1, 2010

    All excellent points. However, as a teacher, when I bring these issues up I am totally ignored and told that I am just another lazy teacher making excuses for school failure. Can you please send this to Obama and Duncan? Maybe they can take their Race To The Top carrots and spend it on the fight against poverty instead of wasting it on charter schools that perform no better than trad public schools.

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