Good Math, Bad Math has a post entitled Economic Disasters and Stupid Evil People which provides a nice summary of how the US financial system got to be in such a mess.

What we’ve been seeing over the last couple of weeks is the same basic scam as the mortgage mess, but on an even larger scale. Lending money is a profitable business. Bundling loans into investment vehicles is an incredibly profitable business for producing what appear to be high-yield, low-risk investments.

Naturally, when there’s a big opportunity to make lots of money, there’s a ton of people looking to get in on it. Of course, just like with the mortgages, there’s a limit. Realistically, there’s only a certain amount of money that can be loaned at any time to people who can pay it back. But there was so much money to be made that as the high-quality loans ran out, they started looking for other things that they could wrap up as investments. Of course, since people who buy these kinds of investments are typically looking for something really safe, that means that they can’t just give money out any-which-way; they need to have some plausible way of saying “This is really safe”.

And here’s where the stupidity really started kicking in.

How do you take a bunch of loans that might not be repaid, and turn them into something that’s safe? Well, what do you do if you had a lot of money tied up in a piece of property that you could lose in an accident? Like, say, a car or a house? You’d buy insurance!

That’s basically what the investment firms did. They gave out shit loans that any sane person should have known couldn’t be repaid, and then they bough insurance on them to guarantee that at least the principal would be safe.

So who did they buy insurance from? Mostly each other.

The whole article is worth a read, as are his earlier pieces on the Subprime Crisis: Part 1 & Part 2