The refinancing rate that the ECB cut today has been at 0.75% since last July: Higher than the Federal Reserve's main policy rate, and the Bank of Japan's, and the Bank of England's.

BBC: ECB takes (a little) action

The main reason for this is that the Bank of Japan, the central bank of a country with a habit of setting economic records of all the wrong sorts, has intervened more heavily in currency markets than any country has ever done before to slow the yen's rise.

ECONOMIST: Buttonwood: Dollar dilemma | The

The main bank, Bank of Tokyo-Mitsubishi, is Japan's strongest (a relative term) and until a few weeks ago the world's largest.

ECONOMIST: Mitsubishi

The Bank of Japan relies on the asset buying program as its main economic policy tool because Japanese interest rates are already near zero percent.

FORBES: Strong Yen Hurting Japanese Economy

Investors called on the Bank of Japan, which three weeks ago reduced a peripheral interest rate, to cut the main rate, raised from 0% to 0.5% in August on hopes of a recovery in the country's economy.

BBC: Japan stocks hit 15-year low