What credit default swaps are and why they should be banned

Willem Buiter has a long and useful description here of credit default swaps, refutes the argument supporting them, and makes 6 arguments against them. He concludes:

The endless churning of contingent claims, including derivatives, when the purchaser has no identifiable insurable interest, turns financial intermediation into a market-mediated betting shop. Then the betting slips become bearer securities and are themselves traded, either OTC or on organised exchanges, and the derivative transactions volumes expand to dwarf the transactions in the markets for the underlying financial claims (let alone the markets for the underlying real resources). At that point, the betting tip of the financial tail of the real economy dog does all the wagging. It does not create value but redistributes it in a way that consumes real resources and exposes the real economy to unnecessary risk. It's time to tame the tiger.