[csense]

Defined benefit plans have a fatal flaw: If the promised benefits don't match investment returns, the difference has to come from somewhere. It comes from some combination of broken promises, higher taxes, higher interest rates and inflation. All of which are political hot potatoes.

Defined contribution plans don't have the same flaw. What you get out of it depends on how much money you put in and how much alpha your investments get. If you don't have enough to support a comfortable lifestyle in retirement, it's not the government's fault, it's user error: You didn't put enough money in, or you didn't invest it properly. The politicians set up systems to help you; "If you didn't use them properly, too bad, so sad, but it's not our fault," they say.