Pouring government tax money into private markets distorts their function. The reason we love Alan Greenspan is he stays out of the market as much as possible. Social Security should not be dependent upon the private markets since it is particularlly when these fail that people need an alteranative for coping. All the money pouring into the markets will serve mostly to make the brokers rich and inflate the price of stocks. This creates paper wealth for private investors, but also increases the danger of an overvalued stock market collapsing. We need a social security system which co-exists with the private markets but is not so intertwined that it can collapse at the same time. The whole point of government is to take care of thing the private market can't or won't. I aggree that investing social security money in other forms of capital, such as the edcuation of children, makes the investment less vunerable to market swings. Good luck.
