One of the most durable myths in public policy circles, both in Washington and in state capitals, is that government spending on universal pre-kindergarten programs generates huge benefits that save taxpayers money in the long run. Members of Congress, governors, state lawmakers — most of them buy this theory, sight mostly unseen, and favor expansions of Head Start, universal pre-K based in public schools, and other dubious, costly proposals.

Virginia is the most recent case. Gov. Tim Kaine has proposed a $300 million program to provide universal pre-K to four-year-olds. Apparently considering him a piker, the D.C.-based Economic Policy Institute just endorsed an $847 million-a-year program for Virginia that would include younger children and higher costs. Set aside for the moment the attempted intrusion into family child-care arrangements and unwelcome expansion of government-run education. The investment argument for universal pre-K is just bunk. There are a handful of university-run preschool programs for severely disadvantaged children that have posted large reductions in criminality, school dropouts, welfare dependency, and other future costs to taxpayers. But expecting these results to be replicated on a large scale, and for children who have functioning parents and safe, stimulating home environments, is ridiculous. What’s really being proposed here is a government program to alleviate the cost of day care for middle- and even upper-income households.

Big surprise: many parents find that prospect alluring. Thus politicians, even moderate and “conservative” ones, find the idea politically alluring. Ugh.