Wednesday, March 4, 2015

Economist Hansuhek Gets It Wrong Again

When you want a bunch of legit-sounding baloney about education, call up an economist. I can't think of a single card-carrying economist who has produced useful insights about education, schools and teaching, but from Brookings to the Hoover Institute, economists can be counted on to provide a regular stream of fecund fertilizer about schools.

So here comes Eric Hanushek in the New York Times (staging one of their op-ed debates, which tend to resemble a soccer game played on the side of a mountain) to offer yet another rehash of his ideas about teaching. The Room for Debate pieces are always brief, but Hansuhek impressively gets a whole ton of wrong squeezed into a tiny space. Here's his opening paragaph:

Despite decades of study and enormous effort, we know little about how to train or select high quality teachers. We do know, however, that there are huge differences in the effectiveness of classroom teachers and that these differences can be observed.

This is a research puzzler of epic proportions. Hansuhek is saying, "We do not know how to tell the difference between a green apple and a red apple, but we have conclusive proof that a red apple tastes better." Exactly what would that experimental design look like? Exactly how do you compare the red and green apples if you can't tell them apart?

The research gets around this issue by using a circular design. We first define high quality teachers as those whose students get high test scores. Then we study these high quality teachers and discover that they get students to score well on tests. It's amazing!

Economists have been at the front of the parade declaring that teachers cannot be judged on qualifications or anything else except results. Here's a typical quote, this time from a Rand economist: "The best way to assess teachers' effectiveness is to look at their on-the-job performance, including what they do in the classroom and how much progress their students make on achievement tests."

It's economists who have given us the widely debunked shell game that is Valued Added Measuring of teachers, and they've been peddling that snake oil for a while (here's a research summary from 2005).  It captures all the wrong thinking of economists in one destructive ball-- all that matters about teachers is the test scores they produce, and every other factor that affects a student's test score can be worked out in a fancy equation.

And after all that, experts (and economists pretending to be experts) have figured that a teacher affects somewhere between 7.5% and 20% of the student outcome.

Now when Hanushek says that teachers make a huge difference, he is obliquely referencing his own crazy-pants assertion that having a good first grade teacher will make you almost a million bucks richer over your lifetime (you can also find the same baloney being sliced by Chetty, Friedman, and Rockoff). Both researchers demonstrate their complete lack of understanding of the difference between correlation and causation.

Remember that, as always, they believe that "test scores" equal "student achievement." They note that students who get high test scores grow up to make more money. Clearly, the test scores cause the more-money-making, right? Or could it be that (as we already know) students from wealthier backgrounds do better on standardized tests, and that students from wealthier backgrounds tend to grow up to be wealthy adults?

So, in short, what we know about the "huge difference" created by Hansuhek's idea of a "good teacher" is pretty much jack and also squat. But he's going to build a house on this sand sculpture of a foundation.

Without knowing the background, preparation or attributes that make a good teacher, we cannot rely on the credentialing process to regulate the quality of people who enter the profession. Therefore the most sensible approach is to expand the pool of potential teachers but tighten up on decisions about retention, tenure and rewards for staying in teaching.

Since we don't know how to spot good teachers, says Hanushek, we should get a bunch of people to enter the profession and then throw a bunch of them out. This is a fascinating approach, and what I really want to see is the kind of promotional brochures that Hanushek would help college programs design. "Come run up over $100K of debt on the off chance that you might be one of the lucky few to get a career in teaching." Or maybe "Do you think teaching might be the work you want to do, maybe? Well, don't get your heart set on it, but do commit to years of expensive education to test the waters." How does a career counselor even approach this subject? "We'd like all of you to commit to this profession with the understanding that we plan to find half of you unfit for it." How exactly do you talk a student into pursuing a career that you don't think he's fit for?

Evaluation of teacher performance becomes key. Gains in student achievement should be one element, because improving student achievement is what we are trying to do, but this is not even possible for most teachers. Moreover, nobody believes that decisions should be made just on test scores. What we need is some combination of supervisor judgments with the input of professional evaluators.

What? What??!! Improving student achievement aka test scores is what we're trying to do? First, which "we" do you mean, exactly, because I certainly didn't enter teaching dreaming of increasing standardized tests scores. And what do you mean "this is not even possible for most teachers"? I mean, it could be a sensible statement, acknowledging that most teachers do not teach subjects that are measured by the Big Standardized Test. And if "nobody believes" that the judgment should be made just on test scores, why would you say that raising test scores is "what we're trying to do"?

And "professional evaluators"? Really. That's a thing? People whose profession is just evaluating teachers? How do you get that job? How do you prepare for that job? Is that what we're going to do with all the people we talked into pursuing teaching as a career just so we could have excess to wash out?

Hansuhek closes by trotting out DC schools as an example of how the test and punish, carrot and stick system works so super well. Would that be the system that was revamped to not include test scores because they were such a mess? Or is he thinking of the good old days when She Who Will Not Be Named used the system to spread fear and loathing, creating an atmosphere ripe for rampant cheating?

There's no evidence, anywhere, that test-based accountability improves schools. None. Not a bit. Not when it's used for "merit pay," not when it's used for hiring and firing decisions, not when it's used for any system of carrots and sticks. Nor could there be evidence, because the only "evidence" folks like Hanushek are looking at is test scores, and test scores are a measure of one thing, and one thing only-- how well students score on the Big Standardized Test. And there is not a link anywhere that those test scores mean anything else (and that would include looking back to the days when US low test scores somehow didn't stand in the way of US economic and international success).

It's tired baloney, baloney sliced so thin that it's easy to see through it. You may want to argue that I am just a high school English teacher, so what do I know about big-brained economics stuff. I'd say that if a high school English teacher can see the big fat hole is your weak economist-generated argument, that just tells you how weak the argument is. Hansuhek has become one of those go-to "experts" whose continued credibility is a mystery to me. He may an intelligent man, a man who treats his mother well, and is fun to hang out with. But his arguments about education are baseless and unsupportable. If you're going to read any portion of the NYT debate, I recommend you skip over Hanushek and check out the indispensable Mercedes Schneider, whose piece is much more closely tied to reality.


  1. What can you expect from the person who invented VAMs for evaluating teachers in 1971 and has been pushing them ever since? This is also the person who advocates against additional funding for schools because "the existing knowledge base does not ensure that any added funds will, on average, be spent wisely. That is true even if some schools may spend their funds wisely" and has been a very well-paid "expert witness" in 20 cases for the states being sued for inequitable funding. From what I can tell, Hanushek is the main culprit for us being in this surrealistic reformster nightmare.

  2. As an economist, I'm sure Hanushek feels compelled to ignore all of the pointed critiques that have come from the math community culminating in the American Statistical Associations refutation of the use of VAM's for individual teacher and school evaluations.

  3. As an economist, I'm sure Hanushek feels compelled to ignore all of the pointed critiques that have come from the math community culminating in the American Statistical Associations refutation of the use of VAM's for individual teacher and school evaluations.