(The Arizona Star http://www.blogger.com/www.azstarnet.com/news/140574)
First of all, all public schools are not alike. All private schools are not alike. The study presents an aggregate of test results for all schools all over the country. Private schools range from high class prep schools for the scions of the very wealthy to modern day segregation academies that meet in the basement of the Church of the Self-Righteous Holier Than Thou Better Looking Christians. Many charter schools and alternative public schools concentrate on troubled students. Public schools serve different student populations, even within the same city.
Second, all students are not alike. Race, socio-economics, and culture all play a roll in students' success. Ontop of that, each child has his or her own learning style. Across the board, students with parents or other adults who care about their education do better than those without the support and respect for education.
Third, even if private schools are better than public schools (which I'm not conceding), vouchers won't help.
Private schools don't have to serve all children, and they won't. If a kid doesn't behave or achieve in a private school, they can and will kick him out. Public schools can't do that without great cause. In the old days, most kids dropped out by 6th grade. Now we are trying to educate more kids for a longer time. Public schools don't give up on kids, and that's a good thing.
Private schools cost a lot more than $1000 a year. A tax credit, even a refundable one, isn't going to help a family that can't come up with the tuition up front.
Public schools need money to serve students well. As I've said before, throw money at the right places. Throw money at the faculty and staff of schools. Trust them to know their children and families and teach them well. Hold them to tough but reasonable standards. And remember that they are teaching everyone.