According to the Center for Retirement Research at Boston College, Social Security provided 72.7% of non-earned income of those aged 65 and older in 2004.  Pensions, assets, and other sources of income represented 17.4%, 6.6%, and 3.3% of non-earned income, respectively. (p.2, Fig. 2)

*Note: Information based upon Current Population Study data.

Center for Retirement Research at Boston College. (2006, March). 401(k) Plans are Still Coming Up Short. Chestnut Hill, MA: Munnell, A.H., and Sunden, A.

"The release of the Federal Reserve's 2004 Survey of Consumer Finances (SCF) is a(n)…opportunity to reassess the role that 401(k) plans are playing in the provision of retirement income. The SCF is a triennial survey of nationally representative sample of U.S. households' assets, liabilities, and demographic characteristics....The 2001 survey showed that 401(k) accumulations were coming up short. The 2004 survey shows some progress but most of the problems persist.