In its 91 years in existence, the National Bureau of Economic Research has created things like the measurement we now know as the gross domestic product and the mechanism for declaring the beginnings and ends of recessions. In the process, it has drawn on the scholarship of 16 of the 31 American winners of the Nobel Prize in Economics — including Paul Krugman.
All of which is a very roundabout way of saying there is a snowball’s chance I could dissect for you the equations underlying one of the bureau’s newest working papers, which purports to calculate the dollar-value good and bad teachers represent to the U.S. economy.
According to the paper’s author, Eric A. Hanushek, a high-quality teacher with 20 students is worth $400,000 per year more than his or her average colleagues, based on pupils’ future earnings. If this rock star teacher has more students — and what public school teacher doesn’t these days? — the economic effect is even bigger.
What’s above average here? “A teacher one standard deviation above the mean effectiveness.” Yep — standard deviation: Only statistics geeks and masochists will want to read the full paper. The rest of us can be content with others’ synopses.
By the same token, “replacing the bottom 5-8 percent of teachers with average teachers could move the U.S. near the top of international math and science rankings with a present value of $100 trillion,” Hanushek argues.
If you’ve been paying attention to the white-hot national debate on teacher quality and tenure reform, you will already have sensed that this is where the stodgy statistics bus gets T-boned by a fleet of ideologically fueled assault vehicles.
Clearly students are more likely to excel in later life — and presumably contribute more to the aforementioned GDP — when they’ve been blessed with great teachers. The chief rubs, of course, are how we identify and deal with the malingerers, and how we account for the fact that teacher quality has little to do with whether a student in precarious circumstances shows up ready to learn.
(An interesting aside: You know who can identify the best and the brightest virtually every time, without any fancy performance metrics? Kids. It’s true — Bill Gates says so.)
U.S. Education Secretary Arne Duncan and many reformers would like teachers evaluated and compensated in part on student achievement, districts better empowered to terminate poor performers and free to hire and place teachers based on factors other than seniority.
A nasty, election-year clash over these proposed reforms during last year’s legislative session cost Minnesota its chance for one of Duncan’s controversial Race to the Top education stimulus grants. Newly seated Gov. Mark Dayton seems to think he can persuade the secretary to give the state another chance; look for more on that in this space soon.
But Hanushek isn’t suggesting that simply firing a particular number of teachers — or, to use his parlance, “deselecting” them — and installing new ones in their classrooms will have an automatic return. He points to recent research [PDF] by the consulting firm McKinsey & Co. examining the 25 highest performing school systems worldwide.
The high achievers “do not allow ineffective teachers to remain in the classroom for long,” but they go a lot further than weeded out duds, according to McKinsey. They make sure that the right candidates are steered into teaching, that the new recruits get excellent help with professional development and that their pupils have the right support to excel.
In South Korea, teachers are drawn from the top 5 percent of their classes; in Finland, the top 10 percent. By contrast, most mainline U.S. teacher preparation programs draw from the bottom third.
Lastly, most of McKinsey’s top-performing systems paid their rigorously prepared teachers 95 to 99 percent of GDP per capita.
Which presents a tidy segue back to the changes to teachers’ performance evaluations and job protections policymakers say they need in order to enact meaningful reforms: Perhaps better compensation and workplace changes giving teachers adequate prep time and the ability to work in collaborative teams would go a long way toward attracting and retaining so many of the best and the brightest that all of this debate about “deselecting” could become history.
At a potential payoff of $400,000 a year per quality teacher, it certainly couldn’t hurt to try.