Since August 2007, the world economy has fallen into recession and has been confronted with a severe financial crisis. In the context of what is now a world-wide recession, what hope can we place in announced fiscal stimulus plans? Will the fiscal stimulus plans decided and implemented in both the euro area and the United States since end 2008 be adequate responses, most notably in the face of the current systemic financial crisis? This document provides an evaluation of the effectiveness of fiscal policy and of current stimulus plans. It indicates that, while the fiscal stimulus measures will undoubtedly prove to be useful in limiting the scale and duration of the downturn, they won’t be sufficient by themselves to prevent a lengthy recession followed by a tepid recovery. In order to maximise the effectiveness of the stimulus plans, these should be accompanied by accommodative monetary policy. Furthermore, in view of accelerating and underpinning a recovery in world-wide economic activity, fiscal and monetary policies will also have to be supplemented by measures aimed at re-establishing properly functioning banking and financial sectors.