Friday, January 19, 2007

Brad DeLong: Charles Murray and Michael Barone Once Again

Why Oh Why Can't We Have a Better Press Corps? (Michael Barone: Intellectual Garbage Scow Edition)

Mark Thoma does intellectual garbage pickup on the overrated Michael Barone.

He tackle's Barone's claim that "maybe" the fall in social mobility in America is due to the fact that a high IQ genetic elite has risen to the top of the fair meritocracy that is our society. And Mark's head explodes:

"Economist's View: Does Michael Barone Believe the Poor Lack the Genetic Intelligence and Drive Needed to Compete in the Emerging U.S. Meritocracy?: Am I reading this column by Michael Barone correctly? Does it blame being poor on lack of intelligence? Do you believe, as he does, that if you are poor it is most likely because your parents were unintelligent?... Read it yourself....

"'Michael Barone: [P]olls show that Americans think their chances of moving up are better than a generation ago. Statistics tell a different story: There is a higher correlation today between parents' and children's income than in the 1980s, and the income gap between college graduates and non-graduated doubled between 1979 and 1997.

"'"America," concludes Parker, "is becoming a stratified society based on education: a meritocracy."... [This] is exactly what Richard Herrnstein and Charles Murray predicted for America in their controversial book The Bell Curve, published 11 years ago. Herrnstein and Murray noted that intelligence is both measurable and in some large but unquantifiable part hereditary, an unexceptionable finding for experimental psychologists but maddening to social engineers. As college education becomes open to all with the requisite intelligence, graduates will tend to marry graduates and produce children with similar intelligence, while others will tend to produce children without it.

"'"Unchecked, these trends," Herrnstein and Murray wrote, "will lead the U.S. toward something resembling a caste society, with the underclass mired ever more firmly at the bottom and the cognitive elite ever more firmly anchored at the top."... Are we there yet?... [M]aybe so.

"'Yet should we be so gloomy?... Not everyone has an emotional need to be on top: How many people, if they thought seriously about it, would really want the burdens of a CEO, however lavish the pay?... As Murray has written, all you need to do to avoid poverty in this country is to graduate from high school, get and stay married, and take any job. The intelligence needed to get a place in the cognitive elite may become more concentrated in a fair meritocratic society, but the personal behaviors needed to find a valued place in society are available to everyone. Meritocracy may mean less mobility, but that is bearable if, as Brooks says, "America is becoming more virtuous."...'"

The inheritance of inequality is strikingly large in America today: if the father's lifetime was 100% above the American average for his day, the son's lifetime income will on average be 65% above the American average for his day. That's a lot of inherited inequality. Is this unequal distribution of wealth, income, and status in the United States today the result of the fact that a genetic elite has risen to the top in a "fair" IQ-driven meritocracy?

No.

This high degree of inherited inequality isn't because high IQ genetic eliteness genes are being passed down from fathers to sons. As Samuel Bowles and Herbert Gintis (2002), "The Inheritance of Inequality," report:

"The direct effect of IQ on earnings... presented in Bowles, Gintis, and Osborne (2002a)... is 0.15, indicating that a [one] standard deviation change in the cognitive score, holding constant... remaining variables... changes... earnings by about one-seventh of a standard deviation.... An estimate of the causal impact of childhood IQ on years of schooling... is 0.53 (Winship and Korenman 1999). A rough estimate of the direct and indirect effect of IQ on earnings... is then... 0.15+(0.53)(0.22) = 0.266....

"h is the heritability of IQ.... The value cannot be higher than 1, and most recent estimates are substantially lower, possibly more like a half or less.... [C]ouples tend to be more similar in IQ than would occur by random mate choice.... [The] genetic correlation of parent and offspring [is] (1 + m)/2....

"Using the values estimated above, we see that the contribution of genetic inheritance of IQ to the intergenerational transmission of income is (h2(1+m)/2)(0.266)2 = .035(1 + m)h2. If the heritability of IQ were 0.5 and the degree of assortation, m, were 0.2 (both reasonable, if only ball park estimates) and the genetic inheritance of IQ were the only mechanism accounting for intergenerational income transmission, then the intergenerational correlation [of lifetime income] would be 0.01, or roughly two percent the observed intergenerational correlation [of lifetime income between parents and children]."

Two percent is simply not a large number. Factors that currently account for two percent of lifetime earnings inequality are simply not yet a big deal, and cannot be responsible for the fall in social mobility.

If there is ever to be a genetic elite, its members will surely exhibit two behavioral traits: a facility with math, and a near-intinctive tendency to do back-of-the-envelope quantitative checks of assertions. We can conclude only one thing from Barone's column: neither he nor his descendents (unless they get really lucky in their mates) are plausible candidates for membership in any "genetic elite".

It is worth pointing out that neither Richard Herrnstein nor Charles Murray are plausible candidates for membership in any "genetic elite" either. Let me turn the microphone over to impeccably right-wing Jim Heckman, who comments on The Bell Curve:

"The Book fails for five main reasons. 1. The central premise of this book is the empirically incorrect claim that a single factor - g or IQ - that explains linear correlations among test scores is primarily responsible for differences in individual performance in society at large.... There is much evidence that more than one factor -- as conventionally measured -- is required to explain conventional correlation matrices among test scores.... They do not emphasize how little of the variation in social outcomes is explained by AFQT or g. There is considerable room for factors other than their measure of ability to explain wages and other social outcomes. 2. In their empirical work, the authors assume that AFQT is a measure of immutable native intelligence. In fact, AFQT is an achievement test that can be manipulated by educational interventions. 3. The authors[']... implicit assumption of an immutable g that is all-powerful in determining social outcomes leads them to disregard a lot of evidence that a variety of relevant labor market and social skills can be improved. 4. The authors present no new evidence on the heritability of IQ or other socially productive characteristics.... [T]hey... [compare] IQ... [to] a crude measure of parental environmental influences. This comparison is misleading. It fails to recognize the crudity of their environmental measures and the environmental component that is built into their measure of IQ, which biases the evidence in favor of their position. Moreover, the comparison as they present it is intrinsically meaningless. 5. Finally, the authors' forecast of social trends is pure speculation... the social policy recommendations have an ad hoc flavor to them.... The appeal to Murray's version of communitarianism as a solution to the emerging problem of inequality among persons is a deus ex machina flight of fancy that is not credibly justified."

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