Or set it up in individual accounts, so that you only get out what you put in.

Right now, this is like people putting money into a extra long CD locked in at whatever US Savings Bonds can offer (3%). That isn't a great deal by percentage rate and for locking in your money over such an extended period of time. Even if it was invested on the market CAUTIOUSLY you could gain at least one or two percent in the interest rate. Doesn't sound like much, but that would be talking about trillions of dollars.