Saturday, June 8, 2013

Revisiting the Chetty, Rockoff & Friedman Mole Hill | School Finance 101

Revisiting the Chetty, Rockoff & Friedman Mole Hill | School Finance 101:

Revisiting the Chetty, Rockoff & Friedman Mole Hill

My kids and I don’t watch enough Phineas and Ferb anymore. Awesome show. I was reminded just yesterday ofthis great device!
320px-Mountain_out_of_molehill-inator

This… is the Mountain-Out-Of-A-Molehill-INATOR!  The name is rather self-explanatory – but here’s the official explanation anyway:
The Mountain-out-of-a-molehill-inator turns molehills into big mountains. It uses energy pellets to do so. It was created because all his life he was told “Don’t make mountains out of molehills”.
Now, I don’t mean to belittle the famed Chetty, Rockoff and Friedman study from a while back, which was quite the hit among policy wonks. As I explained in both my first, and second posts on this study, it’s a heck of a study, with lots of interesting stuff… and one hell of a data set!
What irked me then, and has all along is the spin that was put on the study, and that the spin was not just a matter of interpretation by politicos and the media, but that the spin was being fed by the study’s authors.
I figured that would eventually die down. I figured eventually cooler heads would prevail. But alas, I was wrong.  Worst of all, we still have at least some of the study’s authors prancing around like Doofenschmirtz (pictured above) with their very own Mountain-out-of-a-molehill-inator!
So what the heck am I talking about? This! is what I’m talking about. This graph provides the basis for the oft-