GDP-linked contracts; direct recapitalisation) points towards a better way of dealing with doubtfully sustainable situations. At debt burdens well below what would be indisputably unsustainable, official lending could embody state-contingent payment plans that would reduce the overhang and pre-arrange the response to unfavourable shocks.
Unfortunately, the science of monetary policy has not reached the point where we can specify a rule for setting policy and turn decision-making over to a computer. Judgment is still required. Nevertheless, I place a great deal of importance on systematic behavior both as prescription for good policy and in terms of my own policy deliberations.