I only read the abstract and the Daily Kos summary, and am not a complexity theorist, but I have to say this seems a little facetious. Sure the valuation proble

I only read the abstract and the Daily Kos summary, and am not a complexity theorist, but I have to say this seems a little facetious. Sure the valuation problem might be np-complete, so technically you can't "solve" it. This has a nice ring and I'm sure lots of members of congress are going to hoist this paper aloft in hearings while they're busy chewing out the CEO of Lehman. But approximation techniques are being used all the time to obtain near-optimal solutions to NP-hard problems. If you can obtain a valuation for a complex bundle of derivatives that's within 10% of the true value, then it seems silly to claim that they whole practice should be tossed out the window. This is like saying salesmen should no longer be able to travel because we cannot solve the traveling salesman problem.