In debate over the voucher scheme, proponents made much out of the legislation’s provision that public schools losing enrollment would retain a portion of state funding for the first five years after a student departed. A similar “hold harmless” provision helped ease the passage of a private school voucher initiative for low income students in the District of Columbia. But harm to public school budgets is not the leading reason that plans like Utah’s are unwise. The cause for concern goes far deeper.

The late Albert Shanker, longtime president of the American Federation of Teachers, articulated something more important. “Our public schools have played a major part in the building of a nation,” he argued. “They brought together countless children from different cultures—to share a common experience, to develop understanding and to tolerate differences....Only public schools are designed to educate every child; only public schools serve to bring many diverse groups together.”

Utah legislators would have benefitted from reading a new report from the Center on Education Policy, entitled, Why We Still Need Public Schools: Public Education for the Common Good. Most of the debate over school vouchers in recent years has been over dueling studies about whether private or public schools raise achievement levels. The most recent evidence shows no private school advantage, once the demographics of students are taken into account. Indeed, education research has long found that what helps students achieve is not whether they attend private or public school, but whether the school has a core of middle class families—who provide positive peer influences, active parental support, and insist on high quality teachers with high expectations.

The Center’s report, written by Nancy Kober, reaches to a more profound level and finds that public schools do a better job of promoting the core functions of education—not just raising test scores but also producing good citizens and tolerant adults, and promoting social mobility and social cohesion. Before other states go over the cliff with Utah, legislators should contemplate the larger democratic purposes of public education.

Richard D. Kahlenberg is a Senior Fellow at The Century Foundation.