An anonymous contributor to the NY Times Freakonomics blog asks "How much does school choice matter?" And answers in much the way you might expect:
Probably less than you think, as [economist Stephen] Levitt has previously argued. Now, in an analysis of seven years of test-score data from 6,000 Los Angeles teachers, the L.A. Times and the Rand Corp. have found teacher effectiveness to be three times more influential than [choice of] school... on student performance.
The author of this posting makes no effort to differentiate between "public school choice" and actual free education markets, and in the process grossly misrepresents what is known and has been repeatedly shown: that the freest and most market-like education systems overwhelmingly outperform monopolisitic school systems such as we have in the United States.
To his credit, Stephen Levitt did make this distinction in the 2007 posting linked in the blockquote above. But even Levitt refered to the evidence on this subject as "hard to find." Should anyone else be experiencing difficulty in finding this evidence, they are encouraged to click on the link immediately above, where they will find a peer-reviewed paper digesting the results of 65 studies on this subject.