THE WORTH OF BUSTING UNIONS?

Iowahawk shows that Texas, a state that prohibits teaches unions, has students that perform somewhat better than the students in Wisconsin.  The dependent measure was NAEP in math, reading and science in both the 4th and 8th grades.   Here are his  numbers for JUST the white students:

2009 4th Grade Math
White students: Texas 254, Wisconsin 250 (national average 248)

2009 8th Grade Math
White students: Texas 301, Wisconsin 294 (national 294)

2009 4th Grade Reading
White students: Texas 232, Wisconsin 227 (national 229)

2009 8th Grade Reading
White students: Texas 273, Wisconsin 271 (national 271)

2009 4th Grade Science
White students: Texas 168, Wisconsin 164 (national 162)

2009 8th Grade Science
White students: Texas 167, Wisconsin 165 (national 161)

These numerical differences seemed small, possibly statistically non-significant. I went to the NAEP data analysis site and ran a statistical analyis on some of the numbers. For the 4th grade math scores, there was a significant difference between the scores of the white students of Wisconsin and Texas, p < 0.0103. The 8th grade science scores were not significantly different, p < 0.2020. and neither are the differences in the 8th grade reading scores, p < 0.1600. However, there is a significant difference in the 8th grade math scores, p < 0.0012.

So, by the 8th grade, Texas only has a statistically significant advantage in math which itself isn't very big considering the scores go from 0 to 500.