From Megan McArdle, at the Daily Beast:
But in the end, they're the same package. There's no way to take the risk out of betting on the future; by the time you can predict the future accurately, it's already the past.
We're just picking how we want to take our risk, not whether we want to take it. And if there's one thing we should have learned form the financial crisis, it's this: the minute we decide that we don't have to make that choice--that we have figured out some way to get rid of the risk altogether--is generally the moment that the universe decides to give it to us, good and hard.
It doesn't matter whether you choose a defined benefit plan (pension), a defined contribution plan (IRA or 401(k)), Social Security, or something else. There is no guarantee that you'll have the retirement of your dreams.