The IMF will slash its forecast for U.S. economic growth in its next World Economic Outlook report, according to Reuters and Italian news agency ANSA. Investors should expect the U.S. economy to grow at just 1.7% in 2013, well below the historical average and 0.3% less than previously forecast. On the bright side, the IMF said last month it could cut its outlook by as much as 0.5% so, in theory, it could have been worse.