You don’t really need to find out what’s going on.

You don’t really want to know just how far it’s gone.

Just leave well enough alone... .

 Don Henley, “Dirty Laundry”

YOU may well be asking yourself, as I have asked myself, how on earth did the credit crisis on Wall Street become such a catastrophe?

How did all of the mechanisms operated by the mind-bogglingly well-paid men and women of the Street go so wrong that we saw a major investment bank, Bear Stearns, essentially disappear? How did Wall Street firms of ancient lineage take such immense losses that they made banks clam up on lending  at great risk to the economy?

Weren’t fail-safe devices in place to guard against risk? Weren’t government watchdogs there to make sure that catastrophes could not happen? Weren’t ratings agencies on the job to police what was going on in the canyons of Lower Manhattan?