Wie Mervyn King, der ehemalige Gouverneur der Bank von England es formuliert hat: „Unser Verständnis der Ökonomie ist unvollständig und entwickelt sich ständig weiter ...
As Mervyn King, the former governor of the Bank of England, put it, “Our understanding of the economy is incomplete and constantly evolving….To describe monetary policy in terms of a constant rule derived from a known model of the economy is to ignore this process of learning.”