Josh Gotbaum explains that we’re unlikely to see sharp curtailing of public pensions through basic considerations of fairness:
Of course, the world changes and sometimes commitments cannot be kept. That’s why we have bankruptcy. Bankruptcy is a process by which people and organizations who cannot afford to keep their commitments can be relieved of some of them. But bankruptcy is not a ‘get out of jail free’ card. It’s a process under which people, businesses and local governments first show they really cannot keep their commitments and then work out a fair way to reduce them. That means that changes in bankruptcy must be both necessary and fair. (State government pensions are in a different situation, because the US Congress hasn’t chosen to legislate a bankruptcy process for states.)
IMO there is some level of public pension—pick a number, $200,000 per year, $300,000 per year—at which the commitment is itself unfair.