Among the risks facing global economies are rising interest rates—as central banks in countries the U.S. and U.K. respond to strengthening economies—geopolitical risks and the euro zone's stalling recovery.
Blanchard was speaking at a time of unrest across many parts of the world, with protests in Hong Kong, ongoing conflict between Russia and Ukraine and threats from ISIS in Syria and Iraq. But he was quick to stress that—to date—there was "little evidence" of their economic impact.
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"But, clearly, the risk that they do so in the future is there, and could affect the world economy in a major way," he added.
With regards to the euro zone's economic slowdown, the IMF highlighted the threat of weakening demand and even a slide into deflation. It comes after consumer price growth in the euro zone slipped again in September, coming in at just 0.3 percent, adding to fears that the region could be heading for a period of growth-sapping deflation.
"This is not our baseline, as we believe fundamentals are slowly improving, but, were it to happen, it would clearly be the major issue confronting the world economy," Blanchard added.
To address these risks, the IMF said that both fiscal policy and structural reforms were needed: "The challenge for policy makers is to re-establish confidence, through a clear plan to deal with both the legacies of the crisis and the challenge of low potential growth."