TOKYO, JAPAN (Reuters) —The negative interest rate set by Japan’s central bank, effective on Tuesday, will add uncertainty to global economy and exert pressure on China’s currency, said economists. The Bank of Japan followed other central banks last month to cut interest rates to minus 0.1 percent to boost economic recovery amid plummeting oil prices and slowing growth in China. The move weakened the yen, which in turn could add pressure on China’s currency […]