For Europe, psychological factors are no less important than in any other currency area. Different causes require different policy reactions. This is the first reason for varying responses of the three central banks. Another – equal important reason – is that they pursue different concepts. The Bank of Japan is in an exceptional situation, anyway.
The US Federal Reserve System was set up in 1913. In accordance with the Employment Act (of 1946) and the Humphrey-Hawkins Act (of 1978), it must pursue several objectives at the same time: economic growth in line with potential output growth, stable prices, a high level of employment and moderate long-term interest rates.