I'm listening to the July 26th PlanetMoney podcast, which actually hearkens back to a podcast from May of 2010, in which they interview the sovereign ratings guys at Standard & Poors. I don't have too much to say on this. But this was from the horse's mouth.
S&P bases their sovereign ratings on two people visiting a country for a week. That pretty much means that every American tourist in history is qualified to do ratings for S&P.
To be fair, they're not riding the Eye, or visiting the Eifel Tower and eating a crepe, they're visiting ministers of finance, and conducting interviews with central bankers. To be fair, the guys they send are fair to midling brilliant, economists, accountants, and analysts, etc. To be fair, mostly the ratings are based on reams of data that they go through in their cozy 49th floor offices in New York. To be fair, all the ratings agencies have proprietary software that's designed to predict using specially designed metrics, on a level far above that of you, or I.
But enough fair: A scientist conducting an experiment will take weeks, months, with controls and double-blinds. They'll have their data peer-reviewed by other scientists. They'll submit it to prestigious journals, which will have the data reviewed again before publishing. Good research takes time. Good research requires cross checks, and several sets of eyes.
And once the two guys come back, they get another three people from S&P around the world, they give brief presentations, discuss and then vote. Sounds like the whole thing gets done in a day. Interestingly, the follow up interview said that this was not always the case, sometimes there are more voters, sometimes it takes a month to make the decision.