Diamond, Peter, and John Geanakoplos. “Social Security investment in equities I”. CRR WP 1999-2, Chestnut Hill, Mass.: Center for Retirement Research at Boston College, 1999. http://hdl.handle.net/2345/4333.
Among the elderly, Social Security income is distributed very differently than private pension and asset income. For the bottom quintile of the income distribution, 81 percent of income comes from Social Security, while only 6 percent is from pensions plus income from assets. For the top quintile, 23 percent comes from Social Security, while 46 percent is from pensions and assets - dramatically different percentages. Similarly, there are great differences in saving and investing among current workers. Among all those who were paying social security taxes in 1995, fully 59% held no stock, either directly or through pension plans. Even among those between 45 and 54 years of age, 50% held no stock, directly or indirectly. These differences have important implications for the proposal to invest part of Social Security trust fund reserves in private securities.