The Wall Street Journal just published a sharply-worded exchange between Eva Moskowitz (former NYC City Council member; now charter school purveyor) and Michael Mulgrew (NYC’s Teacher Union President). It reminded me of the many silly, high stakes school comparisons being made. They are high stakes because many people imagine that they are important. Their spat was an especially silly type of comparison between the test scores of randomly chosen charter enrollees or voucher recipients, for example in Milwaukee, and unsuccessful charter or voucher applicants. Oh boy, the ʺGold Standard″ of comparison; random selection. But the comparison is fraught with wrong, misleading, and irrelevant aspects. First, the comparison assumes virtual irrelevance to the Nation at Risk problem. It assumes that choice expansion does not affect the traditional public schools (TPS)!?!? Though the effects of the restriction-laden programs available to study have been small, the no-effect-on-TPS assumption has been proven wrong repeatedly. So, by ignoring likely gains by TPS students, the measurement of voucher user and charter user benefits is biased downward. Second, random selection of charter enrollees requires charter waitlists; a shortage of space. Since shortages invariably erode the quality of the product, we have a second reason that the measurement of benefits is biased downward.
Third, is that the comparison addresses the wrong question; public vs. private or charter vs. public. The public vs. private or charter vs. public comparison assumes that the differences between two parts of a low-performing system are important. That comparison is only important for programs that are too small to address the ″Nation at Risk″ problem. Addressing the right question requires school system comparisons. The right question: Does the expansion of choice to include private schools and/or chartered public schools improve the overall performance of the school system?
The fourth problem with public vs. private or charter vs. public comparisons is the bizarre complaint that it is unfair. It amounts to a claim that it is more important to be fair to traditional public schools (TPS) than to do right by children. Even with the handicaps the current system imposes on private schools, they often perform better, as group, than TPSs because private schools avoid some of the heroic assumptions of TPSs. So, rather than describe the reasons for that superiority, studies typically ʺcontrol for″ (adjust the raw numbers to eliminate) the advantages of private schools. For example, private schools can ability-group-by-subject, and specialize in certain instructional approaches like Montessori and themes, like sports or athletics, to engage children whose parents decide those settings are a good fit for their children. TPS aim for one size fits all. So, it helps all children to address special needs in specialized settings, as private schools do, but it is unfair to compare TPS that specialize much less — mainstreaming most special needs children, for example — to individual private schools when most private schools do not enroll many types of special needs children. It will only become fair if we very foolishly impose reasons for TPS low performance on private schools and chartered public schools.