Do Teachers Unions Hurt Education?

It's become a standard position of the anti-union right that teachers unions are hurting our kids.  Bad teachers are paid high wages and protected by tenure and other policies,  etc.   It turns out that quite a few states have gone quite far down the path of ending teachers unions.  We can look at the results and find out how it's working.  The top chart is from http://teachersunionexposed.com/state.cfm, a strongly anti-union group, and shows the percentage of teachers who are members of a union.

 

 The second chart is from an article about math and science education: http://www.huffingtonpost.com/2011/07/11/state-education-rankings-_n_894528.html and is based on data from the Statistical Research Center of the American Institute of Physics.

 

There are a few correlations that spring to light immediately:   All but one of the states that have low rates of union teachers have average or worse results in science and math education.  Virginia (10.2% of teachers there are union) is the only exception.   The five states with the lowest union membership: South Carolina (0% union), Texas (1.8%) Mississippi (2.2) North Carolina (2.3%) Arkansas (6.1%) are all near the bottom of the ranking.  

At the other end of the spectrum, most of the union states are doing better than average.  There are a few exceptions:  Nevada and Hawaii (100% union) Alaska (98.3%) Iowa (98%) West Virginia (89.5%) Idaho (88.6%) and California (87.5%) have relatively high union rates and below average results.   Apart from these exceptions, the states with a high percentage of teachers in the union are average or better. 

What does this tell us?  Well, this is a correlation, but not a strong one.   None of the states that have gotten rid of the union have seen their results improve and several (notably Texas) have seen their results decline, while many of the states that have kept the union have seen their results decline too.  What these data tell us is that while there are clear problems, they are not coming from the teachers unions, and by and large, the union is helping more than it's hurting.  That doesn't mean that teachers unions are without fault, but it does tell us that there must be other places to look for the problems in our public education system.  Getting rid of the teachers unions has not solved anything where it's been tried, and according to these data is more likely to hurt than help.