It's back to school time — and not just for kids. Thanks to a new regulation from Washington D.C.'s government requiring that, by 2020, all childcare workers must have at least an associate's degree and center directors must have bachelor's degrees, about half of the city's childcare workers must soon head back to school or lose their jobs.

Getting these credentials won't be easy for these workers. Two years of tuition to obtain an associate's degree at a public schools costs about $7,000; a four-year bachelor's degree, $40,000. City officials are promising to help workers shoulder these costs, but undoubtedly this will still be a big barrier to entering a profession that promises modest pay at best. The Bureau of Labor Statistics estimates that childcare workers in Washington earn an average of about $26,900 per year. That will make it difficult to shoulder any tuition costs, let alone also pay for the supplies and transportation, and find the time to attend classes and complete school work.

Note that childcare workers are overwhelmingly female (women account for 96 percentof childcare workers nationwide), and disproportionately Hispanic (20 percent) and African American (14 percent). These are populations that policymakers are supposed to support and help facilitate work; not make it harder for them to get and keep jobs.

Presumably, the regulations' advocates hope that the childcare workers will be able to demand higher wages once they have better credentials, but Washington already has some of the nation's highest childcare costs: In 2015, full-time care for an infant at a daycare center exceeded $22,000 a year. If it were a state, Washington would be one of the 33 states where average childcare costs are more than in-state college tuition. How much more can working parents afford to pay before working outside the home no longer makes sense?

The average Washington household earns more than $84,000 — that's the highest in the nation, according to the Census Bureau. But a $20,000 childcare bill still eats up more than a quarter of wages, before paying taxes. Many two-earner couples face a situation in which the majority of the secondary earners' income pays for childcare, encouraging more parents, particularly more women, to cut back or stay home. Single parents face a similar, only more difficult, dilemma. Scholars have found that a 1 percent increase in the price of childcare leads to a drop in single mothers' employment of between 0.3 and 1.1 percent. Discouraging these women from working, and presumably relying instead on public assistance, has a lasting impact on their families' prospects.

Of course, there are many very worthy reasons why a parent might opt out of the workforce to care for children. But needlessly exorbitant childcare costs shouldn't be what drives that decision. Public officials shouldn't be promulgating regulations that effectively encourage women to lean out.

Even more depressingly, Washington's new regulation is even unlikely to result in higher quality care for children. Parents know that having a college education isn't what's most important in a caregiver. They want their children cared for by people who are patient, kind, and engaging. Studies such as this Mercatus Center paper found that regulations intended to enhance daycare quality tend to fail, as they encourage daycare centers to focus on the wrong criteria and only succeed in driving up the price.

As Preston Cooper, education analyst for the American Enterprise Institute, put it, the only winners from this regulation are the "thousands of colleges that get to charge childcare workers thousands of dollars to churn out those credentials." The biggest losers are daycare workers, working parents, and children.

This is public policy at its worst. City officials would do far better to help families by joining the movement to roll back counterproductive rules that do far more harm than good.

Carrie Lukas (@carrielukas) is president of the Independent Women's Forum.