It would make more sense to ask the corporations that than to ask me. I think it would complicate the borrowing of money for some of them, but they would know that better.
I want to point out something else about the way these plans are supposed to work. Pension plans used to be unfunded, and then they were funded. The proper way to protect people when these events happen is to have better funded pension plans taking less investment risk.
That's what insurance companies do when they write annuities. They take the money in, they buy bonds, they don't take huge investment risks, and they're well capitalized. So in 2008 the annuity payments continue, the disability payments continue, and the life insurance payments continue.
If what we want to do is have more secure disability benefits or more secure pension benefits in these plans, the natural place to start is with the funding requirements and with the investment rules, as opposed to trying to clean up the mess once the sponsor goes under and there isn't enough money. It's very hard to clean up the mess once you've allowed the mess to happen.