The other major problem is that it wasn't regulation that failed, it was regulators. Many regulations that already existed weren't enforced. Looking at the rate of regulation increase it isn't hard to see why. How do you propose to solve this problem with more regulations? There's a real engineering problem here or even a computer science-style information theory problem with information flows totally exceeding the ability of the processing nodes to handle. Clearly, adding more processing work to be done isn't the answer to that problem, and we probably can't afford enough processors to make even our current set of regulations actually get enforced.
After a regulated industry undergoes regulatory capture you will see is a steady growth in the amount of regulation, and a simultaneous decrease in how much the regulation prevents that industry from doing what it wants. The regulations are added because they benefit the industry in some way, for instance by creating barriers to entry for potential competitors.
That is what happened in finance. Glass-Steagall really kept companies from doing what they wanted to do, and got dropped. But we got new "regulations" like the optional alternative way of calculating net capital ratios introduced in 2004 that allowed the 5 major broker dealers to double their leverage. The result? More lines of "regulation" that reduced how much actual regulating there was. Oh right, and a few years later a bunch of failed broker dealers. See http://www.nysun.com/business/ex-sec-official-blames-agency-... for verification of that.
Therefore a steadily increasing number of lines of regulation is not evidence that there wasn't major deregulation in the same time period.
Most so-called deregulation could be better termed re-regulation, it's just changing the rules to benefit different parties, not abolishing them.
(Having said that, btilly above uses deregulation in its new derogatory sense, much like the euphamism downsizing had to be replaced with rightsizing once everyone realised it still meant redundancies. Relatedly the depression was named that by people who thought it wouldn't be as bad as a proper recession, now depression means a really bad recession)
And in light of the inability of regulators to enforce the regulations and the plain failure of them to do so, who cares what the regulations actually said anyhow?
Additionally the Gramm-Leach-Bliley Act of 1999 that removed the last vestiges of Glass-Steagall (the parts that are related to this argument) happened under Clinton. The trend of financial market deregulation started in 1980, due to a shifting tide in economic though in the neoclassical (chicago school) vein and a multi million dollar banking lobby.
Economic systems need to be designed so that mediocre government regulation doesn't lead to catastrophes.
Eliot wrote: “After all, your pigs are far more intelligent than the other animals, and therefore the best qualified to run the farm – in fact there couldn’t have been an Animal Farm at all without them: so that what was needed (someone might argue) was not more communism but more public-spirited pigs.”
http://entertainment.timesonline.co.uk/tol/arts_and_entertai...
A position that regulation either failed or was absent from banking adds a third choice, which isn't far from Krugman's: 3) better government intervention and fewer problems.