The monthly payout of social security is based on how much you earned while you were working

But the lifetime payout is set by how long you live. Your total recoupment is based on the number of months you receive SS. There is never an age when you lose eligibility.

Even below that cap, there is a progressive structure, where those with a lower income see a larger marginal benefit.

People with low incomes have a host of additional problems - higher stress levels, poorer nutrition, less access to preventative and life sustaining medication.

This lowers their overall life expectancy and - as a consequence - the total recoupment they expect to receive from SS.