Monetary policymakers can also come under particular pressure to take action if a relatively prolonged period of persistently very low inflation sharply diminishes the longer-run inflation expectations, as that could be a factor in keeping future inflation rates too low as well.
At last  2  BIS central bankers’ speeches  report, market-based longer-run inflation expectations, at a value of 1.4%, were indeed well short of our definition of price stability. This finding does not, however, represent evidence of their de-anchoring and thus of the risk of an excessively low inflation rate taking hold.