Government preschool is in vogue at the moment, with New York’s Mayor Bill de Blasio even pushing for a dedicated city tax to pay for it. But de Blasio and other supporters have been remarkably dismissive of the evidence indicating that government preschool has no lasting effects.
When pressed, how do preschool advocates respond to this evidence? By shifting blame to elementary schools. Their argument is that the gains from preschool fade out because of the bad schools that pre-K graduates go on to attend. As the New York Times wrote in a recent editorial, “Skeptics may say that the benefits of preschool tend not to last, but that doesn’t have to be true, if done right and sustained by good schooling in later years.” Writing for Slate this week, Sara Mead put it more bluntly: “Even the best pre-K can’t counteract the impact of ineffective elementary, middle, or high schools.”
Blame-shifting is in fact the official position of the National Head Start Association. It insists that Head Start “does its job,” only for the benefits to, in their euphemism, “flatten out” because of later circumstances, including low-quality elementary schools.
The blame-shifting argument is unconvincing for a couple of reasons. First, government preschool programs have been evaluated with controlled experiments. The children in the control group — i.e., those who wanted to attend government preschool but were not selected — go on to elementary schools that are just as bad as the preschool group’s schools. So if we strengthen the elementary schools, then outcomes for both the preschool and control groups would likely improve. Whether government preschool adds any value in that situation is unknown.
Second, no one knows how to reliably improve elementary schools, at least not in a dramatic way. In fact, one of the reasons preschool became so popular is that policymakers found interventions in the elementary and secondary years to be largely ineffective — now they are circling back to the same old problem.
People can always argue that their favorite social program would be useful if only other parts of society worked better. That’s a non-falsifiable claim. What’s relevant for public policy is whether a program makes a difference in the world as it exists today. Government preschool does not appear to do so.