The middle fifth of the population only gets 16% of its income from retirementfunds and 0.5% from public assistance, and the richest fifth only 4% and 0.1%, respectively.
At that bottom end of the scale, retired and unemployed Americans rely far more on safety nets: the lowest-earning fifth of the population gets 48% of its yearly income from retirementfunds like Social Security, and 9% from public assistance programs like food stamps.
Remember, the exercise then, as now, was to build a portfolio with an allocation that looked just like Vanguard Target RetirementIncome (VTNIX), but using better funds.