This Great Graphic comes from Bloomberg's Business Week, which itself is drawn from IMF data. We have noted before how poorly the IMF has forecast Greek GDP and this helps explain why the debt/GDP ratio is deteriorated more than expected.
The first panel shows how poorly forecast euro area growth. It recently admitted it under-estimated the fiscal multiplier or how much of an economic drag is created by every euro of deficit reduction.
The second panel shows, among the industrialized countries, where the IMF forecasts has been off the most on a per capita basis. Of note, the IMF under-estimated per capita growth in Canada and Japan. The miss in Canada may be due to the positive terms of trade shock. The miss in Japan may be a function of the fact that its output has held up despite the shrinking population.
The third panel shows that despite the misses, overall, the IMF's 2009 forecast for the advanced economies in 2012 was in fact quite accurate, off by 0.1%. While we have been skeptical of true decoupling of the emerging markets from the high income economies, the IMF under-estimated growth in developing Asia by more than a quarter.