social security system

Under the social security system in the United States, workers pay taxes and receive a monthly annuity after retirement. Some have argued that the United States should invest the social security tax proceeds in stocks.
The rationale is that, over time, there is a decreasing probability that stocks will underperform bonds. The social security system would thus benefit from the higher expected return on stocks. Making use of the put-pricing discussion in Section 22.6, comment on this proposal.