A common, although misleading, refrain heard from education reform critics is that charter schools on average do no better on standardized tests than public schools. Less commonly discussed is the impact on other, non-test outcomes. A paper (working version) in the most recent Journal of Labor Economics by Kevin Booker and Brian Gill from Mathematica, Tim Sass from Florida State, and Ron Zimmer from Vanderbilt, looks at how attending a charter schools affects the probability of graduating high school and attending college for a sample of students from Chicago and Florida.

An important question in the literature is the extent to which selection bias is a problem. Do charter school students have different outcomes than public school students because the charters educate them somehow better or worse, or is it because people who decide to go to charter schools are systematically different than those who don’t? In order to control for this they look at the sub-group of students who attended a charter middle school, and compare outcomes for those who went onto a charter high school to those who went on to a public high school. The idea is that selection bias shouldn’t be an issue between those who are already attending a charter school, because as charter school attendees they should be similar in terms of whatever unobservable variables lead to charter attendance.

They find that in both Florida and Chicago, attending a charter high school increased graduation and college attendance rates. In Chicago, students were 7% more likely to graduate from high school if they attended a charter, in Florida it was 12% to 15%. Charters increased the probability of attending college by 8% to 10% in both Florida and Chicago. The authors argue that these results are consistent with the studies on the effects of attending a Catholic school,  and a recent D.C. voucher experiment, both of which have been shown to improve educational attainment.  Consistent with the literature on the affects of charter attendance on test scores, they find that the impact in Florida is stronger in urban areas.

These are important results to keep in mind. Given education reform critics skepticism of standardized testing, I expect results like this will receive more weight for them than studies that look only at test scores.