Whether it’s Mike Rowe (host of the show “Dirty Jobs”) or academics (mostly economists) raising the issue, the need for a college degree is increasingly in doubt these days, given the good wages and dearth of workers in various trades.

Nonetheless, the test of whether someone has received a good education through high school remains how well one fares in first graduating high school and then post-secondary educational pursuits, especially college. This is because a high school degree mostly develops the foundational skills necessary for a lifetime of learning and skills development, regardless of one’s choice of blue-collar or white-collar endeavors. After high school, an individual should have options, and if one is prepared well enough that college is a realistic option, other options are equally realistic as well. For this reason, educational attainment (how far one’s education extends) is a fair test of the success of educational policy.

The research shows that private-school choice improves educational attainment for those who have the opportunity to exercise such choice. Arguably, this is a better outcome of school choice than improved test scores (though school choice accomplishes that, too). Test scores are impacted by “teaching to the test.” That is, if all one wants to do is perform well on tests, one way to do it is to narrow a school’s curriculum and drill students on tested content. This does not necessarily prepare one well for future endeavors; it certainly does not produce a well-rounded individual.

A good deal of research is available on the impact of school choice on educational attainment, but much of it fails the test of having used the highest-quality research methodology, which would be something like a random assignment study using a control group. Though few in number, such studies are possible because most voucher programs are oversubscribed, so it is possible to look at students who receive vouchers and compare their outcomes to those of similar students who did not receive vouchers. Only seven such high-quality studies have been identified by EdChoice, a school choice advocacy organization that nevertheless does a good job of keeping up with the research literature on the subject. Of the seven identified high-quality studies, four show positive impacts on educational attainment from school choice programs. The other three show no effects, positive or negative. The weight of the evidence, already stated, points to school choice improving educational attainment.

As with test scores, it should be noted that school choice is not some sort of magic bullet that produces instant remarkable results. If that were the case, careful statistical studies would not be necessary in order to understand the impact. One reason for this might be that the voucher programs studied are often tailored to demographic groups who are already poor performers, especially when it comes to going on to post-secondary educational pursuits. It’s not that these individuals don't have the ability to attain high school diplomas and more. Instead, it’s most likely that they have to overcome other cultural and financial obstacles to such pursuits. A choice of school can only accomplish so much; it is unlikely to work miracles.

One study, focused on Washington, D.C.’s voucher program, found “compelling evidence” that it had a positive impact on high school graduation rates. A different study that looked at Louisiana’s voucher program, which is limited to students with modest incomes and from low-performing public schools, found that the program made no difference in the likelihood that students would attend college. Yet another study that looked at Milwaukee’s, Florida’s, and Washington, D.C.’s means-tested voucher programs found significant positive impacts on voucher students’ likelihood of attending college, although college completion rates proved disappointing. Washington, D.C.’s program appeared to have no impact on students’ college attendance, although there is evidence that it may well be associated with increased college attendance four to five years after high school graduation.

Modest results are what can be expected from modest programs. School choice alone cannot be expected to overcome embedded cultural values and limited means. Voucher programs often explicitly exclude schools that seek to inculcate values that lead to harder work, greater achievement, and long-term outlooks that lead to investing in oneself. This last policy may well be why the positive effects of vouchers on educational attainment are not greater. Policymakers who write school choice laws should therefore leave as much flexibility for parents to choose schools as is responsibly possible. This is one reason for structuring a school choice program in the form of educational savings accounts, like the proposed Oklahoma Empowerment Act. It legally and responsibly allows parents the widest possible latitude in choosing an educational environment for their children to thrive.