2. Public school teachers aren’t as skilled as private-sector employees with comparable degrees.

Richwine and Biggs base this assumption on the faulty logic of fallacy No. 1, but then they steer their argument into the gutter by using college entrance exam scores to further imply that public school teachers, as a group, aren’t as bright or talented as college graduates as a whole.

Without getting into the accuracy of their data analysis, of which I have no knowledge, I’m surprised to see their argument built around such a limited—and deeply flawed—view of what it means to be a “skilled” employee.

Does emotional intelligence not play a critical role in a teacher’s success? Of course it does. How about communication skills? You bet. The ability to challenge? Motivate? Inspire? Yep. Ditto. Absolutely.

None of these characteristics are measured on the SAT or GRE, and yet they’re instrumental to the teaching profession. Omitting them in a blanket judgment about teachers’ skills and abilities would be like judging the abilities of concert pianists or fighter pilots based on test scores alone.

To use an example that free-market analysts like Richwine and Biggs might appreciate, let’s compare the economic worth of a floor trader on the New York Stock Exchange and an ornithologist at a local museum. Let’s assume, also, that both have a master’s degree.

Does it matter to his economic value that the stockbroker’s GRE scores might be lower than those of the scientist’s? Of course not. What matter most to his professional success are the knowledge he learned in his field of study and the personal skills he brings to his job, such as aggressiveness, self-confidence, quick thinking, good judgment, and analysis—skills that might, or might not, have led to higher scores on his graduate school entrance exam than the bird researcher.

Richwine and Biggs would never dream of suggesting that someone who makes fistfuls of dollars for his high-powered Wall Street firm is worth less money than someone who toils in the back of a dusty museum—even if stockbrokers as a group were found to have lower average scores than ornithologists on standard measures of cognitive ability. So, it’s pretty clear that “cognitive ability” is a poor proxy for overall skills—and it has no bearing on one’s economic worth or earning potential.

Yet, Richwine and Biggs clumsily swap “cognitive ability” for academic credentials in their analysis, just so they can devalue teachers. They didn’t like the results when they compared professionals with similar levels of education, so they manufactured a way to cherry-pick the data that was more favorable to their desired outcome.

This convenient substitution doesn’t make logical sense. Their research paper would have a hard time meeting the criteria for publication on Wikipedia, never mind a serious academic journal.