Quae nocent docent

NB: the "indefinite future" numbers require an increase in payroll revenues of 26%, or a reduction of benefits of 20%. That's a 3.2% increase in current tax rate (12.4 -> 15.6%) if you don't expand the tax base. I don't have numbers for how much Obama's "raise the limits" expands the tax base, or how much a "raise the retirement age to 67/70/whatever" reduces benefits. But really, I'm mostly ok with a 75 year time window, rather than requiring "indefinite future".