One more from Brad DeLong:
Why We Need a Bigger Social Security System with Higher, Not Lower Benefits: Edward Filene's idea from the 1920s of having companies run employer-sponsored defined-benefit plans has, by and large, come a-crashing down. Companies turn out not to be long-lived enough to run pensions with a high enough probability. And when they are there is always the possibility of a Mitt Romney coming in and making his fortune by figuring out how to expropriate the pension via legal and financial process. Since pension recipients are stakeholders without either legal control rights or economic holdup powers, their stake will always be prey to the princes of Wall Street.
That suggests that what we really need is a bigger Social Security system--unless, of course, we can provide incentives and vehicles for people to do their retirement saving on their own. But 401(k)s have turned out to be as big a long-run disaster as employer-sponsored defined-benefit pensions when one assesses their efficiency as pension vehicles.
And so let me turn the mike over to James Kwak: The Problem with 401(k) Plans ...