Fact check on Wisconsin test score claims

Supporters of teachers unions in Wisconsin have claimed the state's college aptitude test scores are second in the nation, while the five states in the country that do not allow collective bargaining rank near the very bottom of the SAT heap. The data shows that strong unions mean smarter kids, they say.

The statistics were picked up by the Atlantic's Andrew Sullivan, and also blasted on the Democratic Party of Wisconsin's Facebook page.

Politifact debunks the claims however, noting that the data used was from 1999--and that the vast majority of students in Wisconsin take the ACT instead of the SAT, making the SAT comparison to other states less relevant. Wisconsin actually ranks 13th in the country on the ACT. That's still a much better showing than students managed in a number of states that don't grant collective-bargaining rights to teachers, such as Virginia, Texas, South Carolina, Georgia and North Carolina. But those states also have higher rates of poverty and a bigger population of students whose first language was not English. In other words, while a lack of union presence correlates with lower test scores in these five states, it's hard to establish a causal relationship.

The correlation between union presence and student achievement also goes beyond college aptitude tests. Matthew DiCarlo took a look at ten states that do not allow binding teacher contracts and test scores from the 2009 National Assessment of Educational Progress (NAEP). He found that only one of the ten states--Virginia--scored above the median.

(Protesters in Madison: AP)