The IMF's World Economic Outlook shows a worrying global economic slowdown, led by Europe and the US.  Among the many causes cited for slowing economic activity is the lack of demand in the private sector.  The IMF's researchers suggest that they expected a quicker "handover from public to private demand." The tsunami and earthquake damage in Japan also bears some of the blame, as do disruption in oil supplies in North Africa this year. 

A lasting, and troubling factor is the lack of confidence on the part of consumers and businesses in developed economies of the West.  The ripple effects of the dip in confidence are being felt around the globe.  Note the impact on growth, as shown in the IMF's Growth Tracker:

From the report:

Worryingly, various consumer and business confidence indicators in advanced economies have retreated sharply, rather than strengthened as might have been expected in the presence of mostly temporary shocks that are unwinding. Accordingly, the IMF’s Growth Tracker (Figure 1.4, top panel) points to low growth over the near term. WEO projections assume that policymakers keep their commitments and the financial turmoil does not run beyond their control, allowing confidence to return as conditions stabilize. The return to stronger activity in advanced economies will then be delayed rather than derailed by the turmoil.

Read the World Economic Outlook, and watch video of the IMF staff discussing their findings, here.