Kevin Carey:

But even as school choice is poised to go national, a wave of new research has emerged suggesting that private school vouchers may harm students who receive them. The results are startling — the worst in the history of the field, researchers say.

While many policy ideas have murky origins, vouchers emerged fully formed from a single, brilliant essay published in 1955 by Milton Friedman, the free-market godfather later to be awarded a Nobel Prize in Economics. Because “a stable and democratic society is impossible without widespread acceptance of some common set of values and without a minimum degree of literacy and knowledge on the part of most citizens,” Mr. Friedman wrote, the government should pay for all children to go to school.

But, he argued, that doesn’t mean the government should run all the schools. Instead, it could give parents vouchers to pay for “approved educational services” provided by private schools, with the government’s role limited to “ensuring that the schools met certain minimum standards.”