(Bloomberg April 3). The Group of 20 leaders who met Thursday in London announced numerous initiatives to boost the global economy while giving the International Monetary Fund additional responsibilities. The IMF, which received a commitment of more than $1 trillion from the leaders, will be charged with warning of impending issues and assessing how G-20 nations are doing on their regulatory and fiscal-stimulus vows. At the summit, leaders also tackled cracking down on tax havens and toughening financial regulations.