(Guest post by Greg Forster)
We now interrupt this serialized political philosophy dissertation on how power corrupts knowledge systems to bring you something completely unrelated – the latest nonsense from the increasingly irrelevant, lifelong Democratic party hack Jack Jennings!
Talk about weasel words. Studies clearly and conclusively finding modest positive impacts from vouchers magically become studies finding that voucher outcomes are “similar” to outcomes at public schools, which then magically become studies provding no “clear” evidence that vouchers have any impact. Never mind that most studies of vouchers have been conducted at Harvard, Princeton, Cornell, Stanford, the Fed, etc. – they’ve been conducted by “pro-voucher” researchers, which is technically true if you define any researcher who does a study finding positive impacts from vouchers as a pro-voucher researcher. (By the same method, you can prove that all studies finding cigarettes cause cancer were conducted by “anti-smoking researchers.”) Extremely minute scrutiny of studies by think tanks have found no scientific flaws in their work, which proves that even more minute scrutiny is obviously needed. And for some reason, a shift in the political winds away from supporting smaller voucher programs toward supporting larger voucher programs is evidence that vouchers are failing! Right, sure they are.
For the record, the empirical evidence supporting school choice is overwhelming – stronger than the evidence supporting any other reform policy. Impact sizes are sometimes large but usually modest, not surprising given that existing programs are tiny, underfunded and overregulated. But the evidence is consistent that school choice produces benefits even under these disadvantageous conditions.
Oh, and more good news: everyone’s onto Jennings’ game, so no one cares about his nonsense. Mickey Kaus:
At this point if Jack Jennings doused himself in gasoline and set himself ablaze in front of the NEA, would anyone notice?
I have Jennings’ professional reptuation hanging on the wall in my trophy room, right next to my Jay Mathews meal ticket.
Jay P. Greene's Blog 
I would add that the CEP report excludes a large number of positive studies from its review without any justification. It does not consider any of the studies of vouchers for disabled students, tax credit scholarship programs, ME and VT tuitioning, etc…
Even with the programs the report includes for review, CEP inexplicably fails to include several studies. For example, it does not mention West and Peterson’s published article on FL or my study with Ryan Marsh on Milwaukee.
And lastly, the report makes no distinction for the quality of the research, so a random-assignment analysis is treated the same as an opinion piece.
This is crap and the media seems to recognize that fact. As far as I can see there is a short piece in Ed Week that focuses mostly on the rhetoric around vouchers rather than the review of evidence. And the Milwaukee Journal Sentinel has a short piece. I’m sure the Army of Angry Teachers will seize upon this, but that will only increase the popular understanding of their unrestrained pursuit of self-interest.
For the record, some of the exclusions they lamely attempt to justify by pointing to their previous lit review – they don’t include anything that was already published when their previous review came out. Which totally makes lots of sense! It really makes the new review highly useful to the reader. Also, what about the studies that had been published when the previous review came out, but were not included in that review because it, too, was cherry-picking?
It was funny reading this where you you refer to a democratic party hack, because you exemplify a republican party hack. You wouldn’t know a scientific study if it hit you on the head. Why don’t you review your study, the win win one, and list out all the scientific and logical flaws (if you need a list i will provide one for you). In case you have trouble getting started, let me give you some help. How about starting a study with defining your terms with some precision, a basic requirement of any scientific study, that your “purported” study lacks. How about the requirement of scientific objectivity, which your study completely lacks (you start with a predetermined view, which you
have been promoting and politicing for., and you are conducted a “study”. Please stop embarrassing yourself. Just acknowledge you have a politically predetermiend view. and avoid any facts or data that go against your view. For example, yuou conveniently fail to include any information about countries who have tried voucher systems on a nationwide level. Not to hard to figure out why yuou did that, is it.
[…] But the study takes the fact that academic gains by voucher student have not been dramatic to use weasel words like "no […]