Bank of Japan cuts key interest rate into negative territory

Japan's central bank is stepping up its efforts to kick-start the country's struggling economy by taking a key interest rate into negative territory.

On Friday, the Bank of Japan announced it would cut the rate on current accounts that commercial banks hold with it to minus 0.1 percent.

The theory is negative ranks encourage banks to lend more and consumer to spend more rather than save. They also can weaken a country's currency, which has the byproduct of helping exporters.

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