From Ezra Klein:
There’s a lot to dislike about Wall Street. The pay. The culture. In many cases, the people. But that doesn’t explain what happened in 2007 and 2008. A lot of observers understood we had a housing bubble — Dean Baker, for instance, had been sounding the alarm for years — but few of the housing skeptics saw everything going on behind the bubble: That the subprime mortgages had been packaged into bonds, that the bonds had been sliced into tranches, that the formulas being used to price and rate the tranches got the variable expressing correlation wrong, that an extraordinary number of banks had purchased an extraordinary amount of insurance against getting that correlation wrong from AIG, that AIG had also priced the correlation wrong and would be unable to pay its debts in the event of a meltdown, that a meltdown would freeze the mostly unregulated shadow market that major financial institutions and players used to fund themselves, that the modern financial system was so fragile that an uptick in delinquent subprime mortgages could effectively crash the global economy.
Read the whole thing.