It appears that Raj Chetty, of the very famous and mostly hypothetical Chetty et al. study addressing teacher quality’s impact on students’ lifetime earning potential, had a big influence on the Vergara case in California:
Testimony in Vergara by Harvard profs. Does anybody–other than Judge Treu–really believe these guys?! Amazing! pic.twitter.com/MvHVCEiUuj
— Gene V Glass (@GeneVGlass) June 13, 2014
But one has to wonder how much impact that testimony would have had if the judge had considered that most reviews of the study find it to be poppy-cock (see Baker on the Chetty et al. molehill and Di Carlo) or if we simply displayed the numbers differently.
A 40-year “lifetime earnings” of $50,000 is only about $1250 a year, or about, after taxes, $75-80 per month, or about 1.5 to 2 tanks of gas a month.
Hmmmm. Compared to the $50,000 of hypothetical life-time earning or that insane $1.4 million for a class of 28, 1.5-2 tanks of gas a month appears to be much ado about nothing.
Chetty also fails to make a very important point about the economics of investing in measuring teacher quality: It will cost billions of dollars in public funding to create and implement a significant increase in high-stakes testing in order to hypothetically raise the monthly earning income of students enough for them to buy 1.5-2 tanks a gas each month.
A much more effective strategy would be to take those billions of dollars needed to create and implement VAM and give every worker in the U.S. $75 per month tax free. Simple, direct, and guaranteed.
Setting aside that this is all hypothetical, seems a ridiculously inefficient cost/benefit analysis of addressing a teacher quality issue that already is only about 10-15% of measurable student learning.
dr. p.l. (paul) thomas 
I really hope the Vergara case is struck down and does not create a precedent. To the extent that there is a “crisis” in public education, it is the crisis of poverty and inequality in our nation, which has a far larger impact on student outcomes than any teacher.