Social security returns

An economist at the American Enterprise Institute ran the numbers:

On average, someone retiring this year can draw a Social Security benefit of about $15,700. If that same worker had a personal retirement account, based on historical returns in the stock market, he'd get $2,300 more than that. That, after two of the worst stock-market downturns in history.

This would be an indictment of the program even if it were solvent in the long term, which it is not.