[I]t's OK to use
college degrees as a hiring requirement... because everyone knows that college is really important and the reason it's not OK to use IQ tests is because everyone knows that IQ tests measure only the ability to take the IQ test.
The italics are Half Sigma's, and signify sarcasm.
Half Sigma goes on to argue, though, that the law makes little difference:
I agree that hiring based on degree does have the effect of making it
more likely that those with higher IQs get into the better career
tracks. But is this the reason why employers look at degrees? Because
they would rather use IQ tests but aren't allowed to?
The average educated person, trained in their beliefs by the liberal
media and liberal college professors, believe that IQ measures nothing
but the ability to take an IQ test. Employers' beliefs are no different
than those of the average educated person. If employers are not using
standardized tests, it's not because they are legally prohibited, but
because they don't believe in them. The laws usually reflect the
beliefs of the majority. If there was a huge groundswell of support for
using IQ testing, the laws would be changed.
On the surface, this seems totally reasonable. The key problem, though, is that on the market, unpopular true views naturally spread via selection and imitation. If IQ tests are really better employment screens than education, then the few employers who hire based on IQ gain a big competitive advantage. They survive and grow, their flexible competitors copy them, and their rigid competitors shrink and die. That's one of the reasons why markets are better than democracy.
If this sounds like mere econo-dogma, consider the rise of index funds. In the 60s, a few academics noticed that dart-throwing chimps could match the performance of fancy investment managers. Most people thought these academics were crazy. Since the academics were largely correct, however, the few people who listened to them got rich and revolutionized their industry. If index funds were illegal, the majority would never have gotten its richly deserved comeuppance.