The story is a little old now, but a week ago the edifying Fat Knowledge posted on the results of a study from an Ohio State University Professor purporting to show a surprising lack of relationship between wealth and IQ.
When crunched for time when reading, I don't always get to the primary sources cited, as was the case with this post. But the claim immediately struck me as absurd--to even be remotely possible, retirement vehicles and home equity had to have been exempted. When I returned to the post a few days later, FK had investigated a little deeper and found that the assertions were basically bunk.
The study's author, Jay Zagorsky, controlled for several factors that proxy for IQ, including divorce rates (making personal sacrifices, waiting for the right person to tie the knot with), years of education (duh), inheritance (the heritability of IQ is generally considered to be around .75-.85), and occupation (because intelligence has nothing to do with whether you choose to be a molecular engineer or a roofer?)! That's like stating that there is no difference between the average height of Chinese peasant farmers and NBA players if you control for shoe size, the femur weight, and pant length.
This evening, I scrolled through the comments on Harvard Economics Professor Greg Mankiw's blog from which FK excerpted.
As a disclaimer, I come in unimpressed with the Prof. When John Kerry loaded the straw that ended his '08 Presidential campaign by insinuating that military personnel are dunces, Mankiw sloppily ran a couple of 'opposing' viewpoints without weighing in himself. I threw my two cents in, pointing out that the DoDEA performs well on the NAEP--its Hispanics and blacks are at the top of their class, and its whites rank third when compared to the other 50 states.
I received no response. Maybe vanity is coloring my irritation, but if military personnel are hopeless dolts, why are their children the smartest the US has to offer? Seems like something that should at least be considered.
To the thrust: Not only is Mankiw's facile vetting of the post embarrasing, the vacuousity with which the vast majority of the commenters approach the subject is startling. Most of them take the 'conclusion' (which Mankiw presents without caveat) as veracious and then proceed to spew silly nostrums about what really matters in wealth accumulation.
Why, in addition to immigration, are economists so stupid in dealing with IQ?
There's the tacit acknowledgement that the wealth of guys like Mankiw attained their stations due to prudent decision-making and hard work rather than the natural talents they were born with. Of course, smart decisions and hard work played a role--but they were underwritten by innate abilities. Being content with that tacit acknowledgement is understandable--that self-made diligence is why Beethoven's lifestory is more admirable than Mozart's.
Another partial answer comes from the similarities that the immigration and IQ issues share--they both inescapably deal with the realities of human biodiversity. Economists think in terms of blank-slatist models, in which humans (or any other vector) receive various levels of inputs and correspondingly produce outputs based on the quantity and composition of those inputs. The inputs are virtually always limited to the extraneous external environment--years of education, years of work experience, exposure to pollutants, etc--and thus can be (favorably or unfavorably) altered at any time. Changing the social system (more affordable education, better work-training programs, etc) becomes the only thing of importance.
Parenthetically, while WSJ editorialists advocate a free-flow of people in tandem with arguing for freer markets and social systems, their assumptions blind them to the fact that the free-flow of those people are going to make their jobs arguing for more liberality increasingly difficult. Similarly, European leftists waving in immigrants from the Muslim world are foolishly dooming the quasi-socialist libertine societies they love. While the WSJ-types hold that there is a universally optimal way for people to make it in life, and the leftists hold that there is no optimal way for a person to live, I hold that there is a universal 'best course' but that it varies contingent upon the makeup of the individual. It's a sort of biological reincarnation of Luther's vocational calling.
So what if the average Mexican migrant has an educational attainment equivalent to the 8th grade? We can get him his GED and some years in college and he'll make big bucks. Even if he doesn't, his kids will be able to as well as any other Joe American does. Of course, we know this isn't the case and it's obvious as to why it's not.
Mankiw and other elite economists are happy to accept the Ohio University study findings, as they suggest that other more malleable inputs--the informational kind of which they dispense--are what truly determines success.
Talk about anecdotal evidence that smart students graduate from Harvard because smart students go to Harvard, rather than because Harvard makes students smart!
But this is another illustration of how they are so often wrong. A couple of major international phenomona are going to further undermine the free-market behavioralist position: China's triumph over India in terms of economic strength and international influence, and post-Kim Jung Il North Korea's supercharged ascent up the development ladder--an ascent that will surpass that of anything de Soto's home country of Peru will be able to do.
Grappling with the social sciences does not necessitate a suspension of 'layman' heuristics like many of the hard sciences (quantum physics) do. Because it's closer to the 'human experience' than say, a hard science like astrophysics, you should leverage what 100,000 years of evolution has primed you to be. It's generally referred to as 'common sense'.