This, from Valerie Strauss “The Answer Sheet” in the Washington Post, is the best concise summary I’ve seen on the performance of charter schools compared to traditional public schools.  There is no meaningful difference:

Charter school critics and charter school advocates should be able to agree that there are excellent and awful charter schools, just as there are excellent and awful conventional public schools. What CREDO and others have shown is that, on average, the two sectors are very similar in terms of test-score outcomes. For those of us interested in improving overall educational opportunities it’s time to set aside the “which sector is better” test-score argument and instead invest across the board in the sorts of practices and supports that the best schools in each sector have provided for their students.

via The bottom line on charter school studies.

If you are not persuaded, read the whole short post.  I think you will be.

Really, it turns out that public schools (unionized or not), charter schools and private schools all get about the same educational results on average.  The improved results come from improved leadership rather than from changing structures.