Then couple the lowering of the retirement age with a lowering of the amount paid out in the early years of retirement, gradually plateauing down to a base UBI level for 40-somethings and increasing to plateau out to a social-security level for 60-somethings.

Well a) SS is barely livable and b) unemployment insurance would actually be a much better proposition if people paid into it.

    > the most basic of subsistence
    > payments, not something we would
    > want seniors to retire with

The full UK pension is £119.30 per week, unemployment benefit (JSA) is: £73.10.

Wow that's nothing. We have state government workers in California getting 90% of their highest salary as long as they live. And some even double dip.

State pension is not the same as the Civil Service pension, which would be equivalent to what you're talking about, and can be very good indeed.