Do charter studies add up?
In this study, Caroline Hoxby, a Harvard professor who studies the economics of education, studied 99% of the nation's charter-school fourth-graders and compared their test scores to those of students at the "nearest" public school. Because many charter schools are located in urban areas, this means she compares charter-school students to a pool of regular-school students who are more low-income than the public school population as a whole. Not surprisingly, then, Hoxby found that charter students perform slightly better than their regular-school peers, and that the longer a charter school is in operation, the better the students do.
This last point is important because charter school advocates believe market forces lead to better schools; the better performance of longer-lived schools is evidence, she argues, that the invisible hand is successfully plucking the winners out of the educational dreck. Her methodology, she says, is a better measure than a "crude" (her term) study by the American Federation of Teachers that analyzed federal National Assessment of Educational Progress data and found charter school students lagging behind their peers. The NAEP data, she argues, includes too small a sample (3% of charter students) and doesn't properly factor in demographic differences.
But to make things even more fun, the AFT released its own study last week finding that regular-school students outperform charter students, and that contrary to stereotype, charter-school students actually have fewer low-income students than regular public schools. "It's funny how when the conclusions don't support someone's philosophy, suddenly there's a problem with the methodology," said Janet Bell of the AFT.
Indeed. Let the data-flinging begin!