Imagine if you will – and it shouldn’t be too hard – that a political impasse has just prevented a country’s government from agreeing a new budget. Or, equally plausibly, that a major bank is circling the drain and has had to be nationalised. Or that a freak storm has wreaked billions of dollars worth of damage to a nation’s infrastructure. Or, as I’m feeling pessimistic, all three. At the same time.

How would this confluence of disasters affect the country's credit rating? What have Standard & Poor's, Moody's, Fitch and the gang got to say? You wait for the rating agencies to pass judgment; and then you wait some more. Losing patience, you get on the blower to demand why these international arbiters of creditworthiness still haven't pulled their fingers out. At the other end of the line a somewhat chastened voice tells you that, sorry, they have only just issued a judgment on that country's rating and you'll have to wait, err, another four months for the next one.