Megan McArdle: "Some studies suggest that voucher programs do modest good; others suggest that they do very little; and a few suggest that the impacts are actually negative. My overall takeaway from the literature is that voucher programs probably do a little bit of good. But the emphasis is on the word "little"; they are not a cure-all, or even much of a cure for anything. It was reasonable to think, in 1997, that voucher programs could change the world. Now we have two decades of evidence.” She points to peer effects, rather than school quality, driving parental choice (see this new NBER paper). "Perhaps it doesn't make much difference what we do in the schools, because most educational effects are driven by a combination of genetics and home environment."
"There’s no value in free college if the colleges lack the resources to educate students. It’s like giving K-12 students vouchers when there are no decent private schools available to to them.” ... "We’ve had an enormous increase in federal financial aid for low-income students, and completion rates are relatively stagnant. Big-picture, something is not working" … "the authors found that spending to improve instruction and academic support has a large positive impact on student enrollment and degree completion." Link.
From the UK, on Voxeu.org: "since the move from a free higher education system to a high-fee, high-aid system, university enrollment has increased substantially, with students from the poorest backgrounds experiencing the fastest increases in participation. Moreover, university funding per head has recovered dramatically since the introduction of fees."