CENTRAL banks in the developed world are no longer acting in tandem. When the financial crisis broke in 2007-08, most banks eased monetary policy significantly. But in late October, two days after the Federal Reserve ceased its third programme of asset purchases, the Bank of Japan stepped up its bond-buying. This divergence seems likely to have a big effect in the medium term, not least in the currency markets.
The Bank of Japan said it was expanding its programme of asset purchases (known as quantitative easing, or QE) from ¥60-70 trillion to ¥80 trillion ($700 billion) a year. Its aim is to ward off deflation, a persistent problem over the past 20 years. The Tokyo stockmarket jumped sharply on the news but the biggest economic impact may be on the exchange rate. The yen fell more than 2% against the dollar on the day of the announcement—a big move by currency-market standards—and hit a seven-year low against the greenback on November 3rd.