The #4 choice actually makes a lot of sense. It will keep those who come to the US in thier 50's as immigrants, work at Wal-Mart for 10 years, and then want to collect after paying in under $10K. If they live 20 years and get $800 a month, they'll end up receiving $192K. Something's wrong with that picture. It will benefit those who have worked their entire life, and penalize those who spent 30 years as a SAHM then went back to work in thier 50's because they "were bored." But if they were making do on one income before, they can do so again in retirement.
Another option would be to never pay out more than someone has paid in. Except for disabled people, as I've stated previously, I do think that people who are disabled to the point that they can not work need to be assured that they will not end up on the street eating out of garbage cans. That said, I don't believe that blindness, deafness, obesity, or a host of other conditions should qualify one for automatic benefits. But that's another thread.
Anyhow, if a limit was placed on benefits where once what you've paid in is gone, you're cut off, with an eventual phase out of the benefit (and the tax) entirely, it might be the way to go. No one would feel entirely ripped off--granted that money could have been invested and made into a small fortune over time--but I'd be happy just knowing that I'll get what I've paid into it back. Maybe make it a double what's been paid in benefit for those who have worked more than 160 quarters--which means they have pretty much worked most of thier entire life with small amounts of time off for childbirth or returning for further educations, etc.
For the truly indigent, perhaps a different social program along the lines of workfare could be established, where they have to continue to work at least part time in order to receive bare bones benefits. Yes, it's punitive, but in all honesty, 20 years from now, anyone without a retirement nest egg accrued on thier own should not be rewarded, knowing what we all know now.
Changes will need to be phased in over time
Anne