The government does not renege on its promises in an active way, through the implementation of new, explicit measures, but it distorts ex ante the "true state of the world". Two commitment mechanisms could mitigate this peculiar kind of time inconsistency. First, independent budgetary institutions could be set up.
But the question is whether we can achieve this simply with rules and supervision? Many a new approach in the world of banking supervision is designed to do just that, but if there’s one thing I can tell you already, it is that they will never go far enough.