What makes fiscal policy (more) effective?

With the world sliding into a global recession, policymakers around the world appear to have fully embraced the traditional notion of stabilization via fiscal expansions. Sizeable resort to fiscal policy seems justified because of the main features of this recession, namely, its expected severity, and the emergence of widespread credit constraints, which makes the transmission of monetary policy weaker and more uncertain. Simultaneously, the global nature of the crisis and the fact that most economies have become quite open to trade strongly argue for coordinated fiscal expansion.