Monday, November 28, 2011

"I only believe in the statistics that I doctored myself"

Here is a really interesting example of "liberal statistics".

In non-unionized Texas, the average SAT scores are lower than in "progressive, unionized Wisconsin". But, if you look at Whites, Blacks, and Hispanics separately, each group scores higher in Texas. (It's just that the proportion of lower-scoring Hispanics and Blacks is higher in Texas than in Wisconsin.)

This is why one needs to know basic statistics to realize that although average A may be lower than average B, each sub-category of A may be on average higher than each corresponding sub-category of B.

So, nationally:
Texas: 47th
Wisconsin: 2nd
But, for 2009 4th Grade Math:
White students: Texas 254, Wisconsin 250 (national average 248)
Black students: Texas 231, Wisconsin 217 (national 222)
Hispanic students: Texas 233, Wisconsin 228 (national 227)
For other grades and disciplines, it's the same: Texas scores consistently higher than WI and national average, while WI scores just barely above (and oftentimes below) than the national average. See for yourself.

So much for Paul Krugman's assertion that not all is well in Texas.

[source: arbat]

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