in which Noah trashes a famous liberal icon math prodigy

Nate Silver - he of the magical statistics models that beat every polling firm in existence, he of the brilliant 2008 campaign coverage - just published a post that contains so many howlers it made my question my faith in the Church of Silver.

Here's the abridged version (I promise I'm not leaving out any key arguments):

Manifestly enough, as we see under Reagan/Bush, the government has some capacity to allocate income to one class to another with its economic policy.

No. No we do not see that. We see that under a presidential regime that was widely reputed to favor the rich, inequality increased. Did that happen because of who the president was? I don't know, and neither does Nate Silver.

It might have been due to shifting patterns of world trade, or the emergence of new technology - the two explanations most cited in academic papers.

It might have been due to structural shifts in the economy caused by the delayed effect of policies taken by earlier administrations.

Or it could be caused by actions taken by Congress, over the objections of Reagan and Bush.

In general, however, the fates of different economic classes are linked. Since 1967, the correlation in the change in year-over-year income between the 10th and the 90th percentiles is .63.

But as any statistician should know, correlation and causation are different things. Roosters do not make the sun rise. That 0.63 correlation might mean that, if we somehow boosted the income of the poor, the incomes of the rich would magically rise...or it might not. It might mean that the economic processes that raise the incomes of one class tend to raise the incomes of another, and that if we intervened the correlation would disappear.

For my money, the Clintonan idea of "aggressive" pro-growth policies coupled with a relatively high tax rate on the rich is an attractive one. Let the rich make their money and then tax them (and/or improve social welfare programs for the poor).

I agree with this, but implicit here is the assumption that taxing the rich doesn't make them stop trying to make money. I am generally willing to buy that assumption, but it shouldn't be buried. If income tax rates for the top bracket went to, say, 90%, it might be a different story.

This was arguably the problem inherent to the credit crisis: each individual businesses had become so good at hedging its own risk that collectively the banks wound up hedging against themselves, the whole system eventually collapsing like a Jenga game.

I agree there was some "tragedy of the commons" going on here, but it appears that Silver has no clear idea of what that was. That's a pretty vague foundation upon which to base a recommendation of "more regulation." If regulation isn't targeted at the key market failures, then we could end up hurting perfectly productive business activity while leaving the true problem unaddressed.

The other potential lesson from the Clinton record, which I've argued may also be observable in the response of the economy to the housing crisis, is that the presence of a robust middle class in fact strongly related to the health of the economy as a whole.

Again, "is related to" does not mean "causes." Taking policy steps to ensure the existence of a strong middle class - for example, Japan's bureaucratically mandated lifetime employment and seniority-based wage policies - may end up hurting the economy in the long run. Or, maybe not. But that's the point, we don't know.

Note, again, that the wealthy actually did better under Clinton than they did under Reagan/Bush, even though Reagan/Bush were trying to stack the deck in favor of the wealthy. The explanation I find intuitively appealing is that there is some sort of optimum supply:demand balance in the economy, and that when too large a fraction of income accrues to the wealthy, this balance becomes out of whack because their are too many suppliers (beyond a certain level of income, the wealthy start to invest/supply their excess income rather than consume it) and not enough consumers.

Maybe hearing the term "supply-side" used as a euphemism for "upward wealth redistribution" has convinced people that "rich people" = "supply". This is not so. Firms (companies) do the supplying, and though rich people own the firms, poor people are employed by the firms. A revenue-neutral shift from corporate income tax to a personal income tax on the top bracket, for example, is a very pro-supply policy, but would redistribute income from the rich to the poor.

Almost all of the countries that are comparably wealthy to the United States have flatter income distributions, the only exceptions being Hong Kong and Singapore (which are as much cities as countries).

According to Wikipedia, the list of countries wealthier than the U.S. includes Lichtenstein, Qatar, Luxembourg, Kuwait, Norway, Brunei, and Singapore. All of which are tiny countries, most of which are oil-rich. So this point is just flat-out wrong. The countries with more equal distribution of income than us are almost all poorer than we are. Of course, so are many countries that are less equal than us.

In fact, equality and wealth follow a U-shaped curve; poor countries are very unequal, upper-middle countries are the most equal, and the richest countries tend to be slightly less equal than those just below them in the distribution.

Did Nate Silver even bother to actually look this up?

In any case, there are a number of good things in this column, and even the faulty assumptions and sketchy half-theories tend to support a policy package I agree with. But this whole post reeks of Thomas Friedmanism - a very smart guy loudly and confidently pushing economic theories fashioned out of news and punditry and lunch discussions, without doing the homework to find out what has already been said by other very smart people who have been spending their whole lives studying this stuff in careful detail.

The economics profession is in a sorry state, but not sorry enough that off-the-cuff stuff like this is a valid substitute. And Nate Silver remains a brilliant man, and a good guy, but even brilliant men and good guys are capable of talking out of their asses.