The study offers no evidence of any causation. A quite plausible explanation — assuming the results would stand up when a different set of voucher and public schools were compared — is that the children of parents, who are more engaged in their academic lives and who are more likely to take advantage of an opportunity to choose schools, are more likely to graduate high school. This wouldn’t be a school effect — but evidence of selection bias.

Here are my thoughts — http://eduoptimists.blogspot.com/2010/02/spin-cycle.html — including the key quote from the AUTHOR of the study — not the press release from School Choice Wisconsin:

“We still don’t know whether it’s going to the voucher school that causes you to be more likely to graduate, or if it’s something about the kinds of families that send their kids to voucher schools would make them more likely to graduate,” he said.

In order:

Larger school districts have their own way of dealing with especially-motivated parents and kids. They’re called magnet schools. Why aren’t these kids graduating from magnet schools? Because they don’t meet the entrance requirements magnet schools set and they’re not doing well in plain, vanilla district schools. If they were doing well what conceivable reason could parents have for jumping through the hoops set by voucher programs.

Claiming that the families are the determinative factor in whether a kid graduates or drops out is so obviously self-serving as to warrant a horse-laugh. If the school is largely immaterial then why do some schools have a lower drop-out rate then others? Those schools just lucky enough, year after year, to get an unusually high percentage of motivated parents? Please.

Suggesting that the results are due to a lowering of standards would set a record for irony if anyone kept track of that sort of thing. Entire states are busy fairly obviously lowering their standards in a bid to keep federal money flowing so if that’s what some voucher-accepting schools are doing they’ve got lots of company.

Let’s try another possibility.

The private schools don’t enjoy the luxury of being dismissive of parental concerns so they try harder then district schools to deal with those concerns. By trying harder to deal with parental concerns those schools are more likely to succeed. The result? Higher graduation rates.

The question is whether they actually earned it or not. I support school choice, but raw graduation rates tell us nothing.

Kids and families who actually take advantage of the vouchers are probably more invested in their education, as opposed to those who don’t feel the need to take any action to improve the quality of their student’s education.

Not to rain on the voucher parade; there certainly are pros and cons to using the system.