Do I really want to get beaten bloody again by school vouchers devotees? Why would I even think of posting such an offensive headline as the one above? Hasn’t my life been better since I stopped mentioning my internally inconsistent view that there is nothing wrong with vouchers, but they are too politically poisonous to help many kids?

The answers: no, I don’t know, and yes. But I am jumping back into the voucher debate because of an updated research report that sheds light on the issue and deserves attention even if it is mostly unfriendly to my point of view.

Greg Forster, a talented and often engagingly contrarian senior fellow at the Foundation for Educational Choice, has expanded a previous study to show that nearly all the research on vouchers, including some using the gold standard of random assignment, has good news for those who believe in giving parents funds that can be used to put their children in private schools. Students given that chance do better in private schools than similar students do in public schools, the research shows. Public schools who are threatened by the loss of students to private schools because of voucher programs improve more than schools that do not have to worry about that competition, the research also shows.

The report is “A Win-Win Solution: The Empirical Evidence on School Vouchers.” It makes my qualms about vouchers look small, petty and illogical, except for one fact that Forster mentions only briefly and whose importance he does not discuss.

He says of vouchers: “More than 190,000 students use these programs to attend private schools using public funds.” That is much less than the 1.5 million students who attend public charter schools, the other major part of the school choice movement. Why the difference?

Many policymakers and politicians resist expanding voucher opportunities but support the expansion of charter schools. Among the leaders of the Democratic Party. including President Obama, charters are good but vouchers are bad. Thus voucher programs are often starved for money and political support while charter programs keep growing, with significant grants from the Obama administration. Efforts to create a national groundswell for vouchers have failed. If you tell voters a ballot measure will give their tax dollars to private schools, which only about 10 percent of U.S. students attend, they will often vote against it. Voucher programs have been approved in D.C., Florida, Ohio, Maine, Vermont, Wisconsin, Georgia, Oklahoma, Utah and Louisiana, which provide much of the data Forster uses to make vouchers look good. But despite a new crop of voucher-friendly governors, the prospects for a wave of pro-voucher votes across the country don’t look good, at least not to me.

As Forster puts it: “Existing school choice programs don’t provide enough students, dollars, and freedom to sustain new schools and allow a robust education market to emerge. Only universal vouchers can break the education monopoly and produce the dramatic improvements we need.”

I am impressed by Forster’s data. Among 10 empirical studies that used random assignment to compare kids in private schools because they got vouchers to similar kids in public schools because they didn’t get vouchers, nine studies found that vouchers improved student outcomes. In six studies all students benefited, in three some benefited and in one there was no visible impact. No study found a negative impact.

Of 19 studies examining how vouchers affect outcomes in public schools, 18 found they improved the schools and one found no visible impact. That was the program in Washington, D.C. that has become a lively issue in my newspaper, and in Congress. The Democrats were close to killing it, but the new House Republican leadership seems likely to revive it. Forster says it has not had an impact on D.C. public schools because the money for the vouchers comes from the federal budget, not the D.C. schools budget. Unlike other voucher programs, the D.C. schools lose nothing they care about if many kids use vouchers to transfer to private schools.

I see nothing morally, economically or politically wrong with vouchers. I have never thought that they drained public schools of vital resources. I think a low-income family that gets the chance to choose a private school that suits their child should do so.

But I think such programs have limited growth potential because there are never going to be nearly enough empty spaces in private schools to help all the students who need them. Forster and other voucher advocates say this will change when voucher programs become universal. Then, entrepreneurs will be able to convince investors that they can create a new generation of private schools with the new wave of voucher students.

I think they are wrong about that. The young educators who have led the robust growth of charters prefer to work in public schools. Many voters will continue to resist sending their tax dollars to private schools, particularly with the pressures to cut back government spending that are likely to be with us for many years.

If I am wrong about that, and the political winds blow in a pro-voucher direction, then Forster’s good paper will be a useful addition to the debate. But I think we are better off spending what money we have on public charter schools.

It will take some big change in the culture---at least a half-century away---to give Forster the opportunity for universal vouchers that he hopes for. I am not going to live that long. Charters are the better bet.