Yet the science is what the OSSE invokes to justify its decision. “We continue to educate the general public and others about the importance of those early years. ... The research in the last 10 years is just profound. I think it's policy catching up with research, with science,” Groginsky said when I asked her about the criticism that policy wasn’t fully justified by the National Academies report.

Flaherty and the Institute for Justice, as well as some child-care provider groups themselves, hold that in the absence of a stronger case, the government has no basis to disagree with the contention that the competencies required for supervising young kids are intuitive or can be learned on the job. Certainly, anyway, this is how society approaches parenthood itself, the ultimate child-care role.

This gets at the heart of the matter. Credentialism has become something of a winning issue for libertarians in recent years, even spawning an Obama administration white paper that condemned the spread of pointless licensing regimes for jobs like hair-braiding—and for good reason, as occupational-licensing requirements have sprung up not just around hair salons but also in industries such as floristry and car parking.

In the case of child care, the case against regulatory intervention is more complicated. The government mandates that kids from a certain age—kindergarten age—attend an accredited school or are homeschooled in a demonstrable way. But extending that down to younger ages is deeply fraught. D.C.’s policy makers are right that daycare-aged children have educational needs. But they are trying to address those needs by regulating out of existence the daycare providers that aren’t officially educational. And that raises a host of questions even bigger than how to certify child care.

As Kelly framed it when she was talking to me about not the specifics of the National Academies report, but about child care more broadly, “If people are thinking of child care as just a place for an infant to be kept safe for the day, that's a different conversation than if people view those hours that an infant spends as a part of their learning and development. That's maybe a more fundamental question about the purpose of those spaces than the report necessarily addresses.”

So the District’s new child-care credential policy is based on the recommendation of a report that was asking a much narrower question than D.C.’s government says. Namely, the question it really looked at was: All else being equal, should child-care providers be required to have higher educational credentials? The report offered a qualified yes. But that question, and any question that begins with “all else being equal,” wasn’t the one facing D.C., one of the most unequal cities in America.

D.C.’s education regulators set out to address an issue of social injustice and place the District at the vanguard of early-childhood issues. But in threatening an already tightly limited supply of child care, they took an approach that will almost definitely backfire. Under the new regulations, it’s possible that the capital’s young children may see some improvement in education outcomes—but only if their parents can figure how to afford the tuition to Daycare State University every year. (And keep in mind that parents who rely on child care, unlike those currently funding their kids’ college educations, tend to be young, in their 20s and 30s. They haven’t been saving for decades in preparation for the expense, and they aren’t in their peak phase of lifetime earning. Additionally, they can't expect their kids to earn any money to help with the costs, as some college students do.)