We all know the conventional pieties on education. Schools fail because we don't spend enough on them! We need to spend more!

OK. Except that the personal-finance website WalletHub has just done a good rigorous analysis of public-school spending and quality nationwide, ranking the results by state. They ranked quality on 13 different metrics, not just test scores but drop-out rates, student-teacher ratio, bullying, safety, and so on.

Key point: Washington, DC has the highest dropout rate, the lowest math test scores, the lowest reading test scores and the lowest average SAT scores in the entire country. The District's overall rank on "School-System Quality" was 49th out of 51. For "Safety" the District ranked 51st out of 51.

Yet in per-student spending Washington, DC is way up there, ranked 14th out of 51. Strange, huh?

Five years ago I reviewed Bob Weissberg's book Bad Students, Not Bad Schools, whose title by itself tells you most of what you need to know about public schooling in America.

Nothing much has changed in these five years, certainly not the conventional pieties; nor the width of the gulf that separates the conventional pieties from reality.