I agree with my partners in crime--Congress and the President should be able to conduct responsible budget policies even without putting any of it on autopilot. But they don't conduct responsible budget policies, and, more importantly, we don't hold them accountable for this at election time, and so I think some type of automatic trigger could work.
Pete notes that the triggers are likely to come at the tough points in the business cycle, leading Congress and the President to undo them anyway. If I didn't believe that in December, I certainly believe it after a winter orgy of stimulus packages and bailouts. Stan points out that for entitlement programs, the time horizon is so long that any forecast isn't good for anything but grins. One is complaining about short term concerns, the other about long term concerns.
What would a happy medium look like? Here are some ideas:
The Social Security Trustees extend the projections (the actuaries get cranky when you call it a forecast) out to 75 years, but most of the projection is on autopilot after just a couple of decades, if that long. (Take a look at this table, for example.) We could apply the "sustainable solvency" definition much earlier in the projection period if we were building in a trigger.
We can also be creative on what event is a trigger and what gets triggered. The advent of oral contraception in the 1960s and the legalization of abortion in the 1970s should have triggered a frank discussion of permanently lower fertility rates that found its way into policy. It doesn't matter what your view on Social Security is--you have to acknowledge that lower fertility rates make the pay-as-you-go financing more difficult to sustain. It would have been nice to recognize at that time that as generations were investing less in their children, they should have been paying more for their own retirement or expecting less per capita.
We used to do this with the Advisory Councils. But the 1994-6 Advisory Council was the last one, and the Social Security Advisory Board is far less prominent as an ongoing entity.
I think what we need is some good old-fashioned Congressional hearings, triggered by projections of long-term budget imbalance, with the expectation--imposed by the voting public--that there will be legislation produced to resolve the projected imbalance.