In other words, once long-term inflation expectations -- the norm of prices -- are de-anchored, a central bank's ability to influence inflation is constrained significantly due to the zero interest rate bound. Those in academia might feel that this is somewhat troublesome.
2 Sterling link 1826–1979 Even after the Irish and British pounds were unified, the Bank of England’s commanding banking position in England did not extend to Ireland, which relied on the Bank of Ireland and on an expanding group of its competitors, some headquartered in Belfast, some in Dublin and some in London, to ensure the payments system, including with their own banknotes (though the Bank of Ireland’s monopoly on notes did not apply outside most of a 50-mile radius of Dublin).