Nate Silver gently suggests the S&P analysts may not be terribly bright, brainwise:
What factors is S.&P. looking at when it rates sovereign debt? A country’s debt-to-G.D.P. ratio? Its inflation rate? The size of its annual deficits?
S.&P. does look at each of these factors. But it also places very heavy emphasis on subjective views about a country’s political environment. In fact, these political factors are at least as important as economic variables in determining their ratings.
For instance, the S.&P. ratings have an extremely strong relationship with a measure of political risk known as the Corruption Perceptions Index, which is published annually by Transparency International. These ratings have been the subject of much criticism because they are highly subjective, relying on a composite of surveys conducted among “experts” at international organizations who may have spent little time in most of the countries and who may instead base their judgments on cultural stereotypes.
I don’t know whether or not S.&P. looks at these ratings. But the fact that the two sets of ratings are so closely related is troublesome. It suggests that S.&P. is making a lot of judgment calls about countries they have no particular knowledge about. Keep in mind that even when it comes to the United States, S.&P. made a $2 trillion error that reflects their lack of understanding of the way that bills are scored by the Congressional Budget Office. Are we to expect that they add value based on their perceptions of the political climate in Kazakhstan, or Cyprus, or Uganda?
Meanwhile, the blog Economics Of Contempt, living up to its moniker, suggests the same thing, only way less gently:
S&P was flat-out wrong — no caveats. They are, to put it very bluntly, idiots, and they deserve every bit of opprobrium coming their way. They were embarrassingly wrong on the basic budget numbers, as everyone knows now, so they were forced to remove that section from their report, and change their rationale for the downgrade. (Always a sign that you’re dealing with hacks.)
S&P’s rationale for the downgrade now is based entirely on their subjective political judgement — and their political judgement is wrong. The brilliant political minds over at S&P said that “the downgrade reflects our view that the effectiveness, stability, and predictability of American policymaking and political institutions have weakened at a time of ongoing fiscal and economic challenges.” ...
Look, I know these S&P guys. Not these particular guys — I don’t know John Chambers or David Beers personally. But I know the rating agencies intimately. Back when I was an in-house lawyer for an investment bank, I had extensiveinteractions with all three rating agencies. We needed to get a lot of deals rated, and I was almost always involved in that process in the deals I worked on. To say that S&P analysts aren’t the sharpest tools in the drawer is a massiveunderstatement.
Naturally, before meeting with a rating agency, we would plan out our arguments — you want to make sure you’re making your strongest arguments, that everyone is on the same page about the deal’s positive attributes, etc. With S&P, it got to the point where we were constantly saying, “that’s a good point, but is S&P smart enough to understand that argument?” I kid you not, that was a hard-constraint in our game-plan. With Moody’s and Fitch, we at least were able to assume that the analysts on our deals would have a minimum level of financial competence.
I’ve seen S&P make far more basic mistakes than the one they made in miscalculating the US’s debt-to-GDP ratio. I’ve seen an S&P managing director who didn’t know the order of operations, and when we pointed it out to him, stopped taking our calls. Despite impressive-sounding titles, these guys personify “amateur hour.” (And my opinion of S&P isn’t just based on a few deals; it’s based on countless deals, meetings, and phone calls over 20 years. It’s also the opinion of practically everyone else who deals with the rating agencies on a semi-regular basis.)
I still think S&P's political judgment is probably correct, but perhaps in a kind of blind squirrel sense.