James Ryan:

handful of states and cities around the country sponsor universal pre-K for four-year-olds, including Georgia, Oklahoma, and, most recently, New York City. Others, including Boston, are moving in that direction. Many believe, with justification, that these are wise investments, given the evidence that high-quality pre-K offers long-ranging benefits to students, which can more than make up for the cost of the programs. The nature and extent of these benefits are the subject of debate among scholars and advocates, but one fascinating aspect of these programs has gone largely unnoticed: the reliance on private providers who receive public funding.