As the pie charts below indicates, blacks and Ashkenazim are dramatically under and over represented among the Forbes ranking of the 400 richest Americans, respectively:

Despite being 13.6% of America, Blacks are typically only 0.25% of the Forbes 400 (Oprah), though some years as much as 0.5%. Meanwhile, despite being only 2% of America, Ashkenazim are estimated to be 35.56% of the Forbes 400. Some might dispute these numbers on the grounds that partial Jews get counted as Jews, however this is counterbalanced by the fact that many full-Jews probably get mistaken for Gentiles. Further, partial Jews are often counted as Jews for census purposes, so counting them as Jews maintains consistency, though admittedly, this is not an exact science.

On a scale where the average White American has an IQ of 100 (SD = 15), I assume the average American has an IQ of about 97 (SD = 15.5) and the average Jewish American has an IQ of 110, and the average Black American has an IQ of 85. This means that the average Ashkenazi America scores 0.84 SD higher than the average American and the average Black American scores 0.77 SD lower than the average American.

Jewish overrepresentation

If IQ correlates about 0.4 with cumulative life time earnings, and if IQ causes income, either directly, or via credentials, then Jews having IQs 0.84 SD above the U.S. mean should cause financial success that is 0.84 SD(0.4) = 0.34 SD above the U.S. mean.

Now assuming there are about 242 million American adults, and only 400 of them make the Forbes 400, then making the Forbes 400 requires wealth at or above the top one in 605,000 level. In other words, normalizing the distribution of financial success, you need to be at least 4.67 standard deviations more financially successful than the average American to make the Forbes 400. However based on IQ alone, the Jewish income distribution should be 0.34 SD above the U.S. mean, thus the Forbes 400 requires one to be 4.67 SD – 0.34 SD = 4.33 SD above the Jewish financial mean. In other words, based on IQ alone, one in 136,074 Jewish Americans should make the Forbes 400, compared to one in 605,000 Americans in general.

Assuming there are about 4.84 million Jewish adults in America, this suggests that 4,840,000/136,074 = 35.57 Jews should be on the Forbes 400 (roughly 9% of the list). Instead Jews are roughly 36% of the Forbes 400. This shows that even controlling for IQ, Jewish Americans are overrepresented among the super rich by a factor of four. However before controlling for IQ, they are overrepresented by a factor of 18. This shows IQ can explain 78% of Jewish overrepresentation, with only 22% unexplained.

Black underrepresentation

If IQ correlates about 0.4 with cumulative life time earnings, and if IQ causes income, either directly, or via credentials, then Blacks having IQs 0.77 SD below the U.S. mean should cause financial success that is 0.77 SD(0.4) = 0.308 SD below the U.S. mean.

Now given that you need to be at least 4.67 standard deviations more financially successful than the average American to make the Forbes 400, and based on IQ alone, Blacks should have an income distribution shifted 0.308 SD to the left of Americans in general, the Forbes 400 requires one to be 4.67 SD + 0.308 SD = 4.98 SD above the Black financial mean. In other words, based on IQ alone, only one in 3,483,046 Black Americans should make the Forbes 400, compared to one in 605,000 Americans in general.

Assuming there are about 32.912 million black adults in America, this suggests that 32,912,000/3,483,046 = 9.45 Blacks should be on the Forbes 400 (roughly 2% of the list). Instead Blacks are typically only 0.25% of the Forbes 400 (Oprah). This shows that even controlling for IQ, Black Americans are underrepresented among the super rich by a factor of eight. However before controlling for IQ, they are underrepresented by a factor of 54. This shows IQ can explain about 85% of black underrepresentation, with only 15% unexplained.

Discussion

IQ explains 78% of Jewish overrepresentation in extreme wealth, and 85% of black underrepresentation. What explains the rest?

The most obvious possibility is some kind of multiplier effect. What I mean is that because the IQs of one’s family members tend to regress 40% to the mean of their race, a Black with an IQ of 140, will tend to have parents with IQs of 118, while a Jew with an IQ of 140 tends to have parents with IQs around 128. Thus, even when Blacks have the same IQs as Jews, Jews still have the advantage of higher IQ family members to give them career advice, lend them money, etc.

Another obvious possibility is that other traits, either cultural or genetic, may gives Jews an advantage when it comes to making money, such as more stable families, lower incarceration rates, and a tradition of entrepreneurialism.

A final possibility is that Blacks suffer from anti-Black discrimination and Jews benefit from philosemitic discrimination. This would be mitigated to some degree by affirmative action for blacks.

However a discrimination model is hard to square with the fact that Blacks do much better on measures of fame and popularity than they do on wealth, while for Jews it’s the opposite.