The International Monetary Fund lowered its forecast for global economic growth in 2015, and called on Tuesday for governments and central banks to pursue accommodative monetary policies and structural reforms to support growth. “New factors supporting growth, lower oil prices, but also depreciation of euro and yen, are more than offset by persistent negative forces, including the lingering legacies of the crisis and lower potential growth in many countries,” Olivier Blanchard, the IMF’s chief economist, said in a statement.