Take a good but not great teacher, one at the 69th percentile of all teachers rather than at the 50th percentile (that is, a teacher who is half a standard deviation above the average). She produces an increase of $10,600 on each student’s lifetime earnings. Even a modestly better than average teacher (60th percentile) raises individual earnings by $5,300, compared to what would otherwise be expected. While those numbers are not trivial, they burgeon dramatically once we recognize that every student in the class can expect such increases in earnings. Consider, for example, a teacher with a class of 20 students. Under such circumstances, the teacher at the 60th percentile will—each year—raise students’ aggregate earnings by a total of $106,000. The impact of one at the 69th percentile (as compared to the average) is $212,000, and one at the 84th percentile will shift earnings up by more than $400,000. But there is also symmetry to these calculations. A very low performing teacher (at the 16th percentile of effectiveness) will have a negative impact of $400,000 compared to an average teacher.
This was music to the ears of the nominally-Democrat crowd of reformsters, the folks in the Obama/Duncan axis who insisted that if everyone in the country got an advanced degree, nobody would be poor. ("Masters degree??!" exclaims the Walmart manager. "Then we'll start paying you $35 an hour!").
Hanushek's whole shtick is to slice test scores into pieces of standard deviation. It's Hanushek and friends who came up with the "days of learning" which is just a slice of standard deviation on a test score.
So how did he come up with this connection between good teachers and lifetime earnings? I'm going to over-simplify here, because we're talking about economist stuff here, but it goes pretty much like this: We know that a better teacher is better because their students get higher test scores, and we know that students with higher test scores go onto have generally wealthier life outcomes.
Hmmm. Well, first we've got to ignore the fairly small teacher effect on student success in school. And maybe high test scores cause higher earnings, or maybe it's 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? At this point, we can also call out the data that aren't there. We've had plenty of time to follow the students of high and low VAM teachers to compare how they're all doing and see if there's a pattern then. And somebody could have pursued the biggest question of all-- is there a shred of evidence that raising a student's test score raises their life outcomes?
You would think all of that is more than enough to retire this baloney. But Hanushek has adapted to the new educational preoccupations. In February of 2020 (aka The Last of the Before Times) there he was, insisting that NAEP scores showed we'd have to get better teachers in classrooms soon, issuing a full-on policy analysis from the Hoover Education Success Initiative-- "The Unavoidable: Tomorrow's Teacher Compensation." The Initiative is a gathering of the usual suspects-- the executive committee is Hanushek, Chester Finn (Fordham Institute boss-emeritus), Paul Peterson, and Margaret Raymond (CREDO chief and Hanushek's wife). Only by using test scores to select and recruit the best teachers can we usher in an era of prosperity.
Now, six years later, for some reason Lauren Lumpkin gave Hanushek a call so that he could explain that today's graduates will earn an average of 8% less through their lifetimes. Because they have fewer skills, a thing he knows because of the NAEP math scores ("Oh, you're one of those," groans the Walmart manager. "We'll start you at 8% less than these older guys.")
And that's not all--
He estimated the combined effect of those losses will cost the U.S. $90 trillion through the year 2100.
He explains
“People don’t get very concerned about this, in part because it’s sort of like blood pressure. It’s the silent killer you don’t notice until you notice it,” Hanushek said of the way math achievement will affect the economy. “What it comes out to is a huge number that we have to pay attention to because it affects our position in the world, frankly.”
And I shouldn't just pick on Hanushek, because other economists are out there chicken littling about this, too.
Thomas Kane and a crew at the National Bureau of Economic Research are predicting a lifetime earning loss of $900 billion for all the students enrolled in the 2020-21 school year. Kane is the Harvard GSE guy who stumped hard for Common Core and testing and once published a terrible analogy about how you can't diet without a bathroom scale and a mirror (really).












