We are assuming that they will take on rather less additional debt over the next few years. That seems an entirely reasonable assumption, but of course nobody can know that with certainty, particularly given that low interest rates of the kind now prevailing have not been experienced in New Zealand for many years.
Instability is often thought to originate from a shock, triggered by a piece of information or rumors that may lead to a loss of confidence and panic. For instance, if a given intermediary is in trouble, there could be certain worries, derived from incomplete information, about the financial shape of other intermediaries.