Teachers Unions, ACT/SAT, and Student Performance: Is Wisconsin Out-Ranking the Non-Union States? is a very important post by Angus Johnston. He examines the research connecting the role of teachers unions to student achievement.

I’m going to print an excerpt here, but you’re making a mistake if you don’t read his entire post:

There’s only been one scholarly effort to tackle this problem that I’m aware of. Back in 2000, three professors writing in the Harvard Educational Review did a statistical analysis of state SAT/ACT scores, controlling for factors like race, median income, and parental education. They found that the presence of teachers unions in a state did have a measurable and significant correlation with increased test scores — that going to school in a union state would, for instance, raise average SATs by about 50 points.

Two other findings leap out from the Harvard Educational Review study. First, they concluded that Southern states’ poor academic performance could be explained almost entirely by that region’s lack of unionization, even when you didn’t take socioeconomic differences into account.

And second, and to my mind far more interesting, they found that concrete improvements in the educational environment associated with teachers’ unions — lower class sizes, higher state spending on education, bigger teacher salaries — accounted for very little of the union/non-union variation. Teachers’ unions, in other words, don’t just help students by reducing class sizes or increasing educational spending. In their conclusion, they stated that

“other mechanism(s) (ie, better working conditions; greater worker autonomy, security, and dignity; improved administration; better training of teachers; greater levels of faculty professionalism) must be at work here.”

I’m adding this info to The Best Resources For Learning Why Teachers Unions Are Important and to The Best Resources For Learning About Attacks On Teachers & Other Public Sector Workers In Wisconsin.

Thanks to M.E. Steele-Pierce on Twitter for the tip.