Thus, our presumption has been that the CCyB would be zero most of the time. Current Assessment of Financial Vulnerabilities When, then, would it be appropriate--given this framework--to activate the CCyB? That is, how do we know when financial vulnerabilities are elevated?
These developments do not point to any imminent loss of dominance for the US dollar or the euro. So far, the data do not show substantial changes in the use of international currencies. But they do suggest that international currency status should no longer be taken for granted. Policy frameworks for a fragmenting world  How should central banks respond to these twin challenges?