This article explores the macroeconomic consequences of fiscal consolidations whose timing and composition -either tax-or spending-based -are uncertain. We find that the composition of the fiscal consolidation, its duration, the monetary policy stance, the level of government debt, and expectations over the likelihood and composition of fiscal consolidations all matter in determining the extent to which a given consolidation is expansionary or successful in stabilising government debt. We argue that the conditions that could render fiscal consolidation efforts expansionary are unlikely to apply in the current economic environment.The financial crisis of 2007-9 left advanced economies with average levels of gross government debt breaching 100% of gross domestic product (GDP) for the first time since the aftermath of World War II, as IMF (2011) reports. The IMF now expects most governments in those economies, except for Japan and the US, to begin consolidation efforts by 2012. Politicians in some countries, most notably the UK, argue that fiscal consolidations will ultimately enhance growth but they cite the need to avoid rising debt costs as a key motivation in undertaking fiscal consolidations. Over the medium term, the dominant fiscal trend in advanced economies is a return to a position of fiscal sustainability, particularly when prompted to do so under financial market pressure.Textbook Keynesian analysis suggests that fiscal consolidations inevitably contract aggregate demand, reducing output and consumption. Neoclassical and New Keynesian models, grounded in intertemporal consumption smoothing behaviour, also tend to suggest that temporary public expenditure cuts and distortionary tax increases reduce output, although with some crowding in of private sector consumption in the case of spending cuts.1 Giavazzi and Pagano's (1990) analysis of fiscal consolidations in Denmark and Ireland in the 1980s, however, suggests that such fiscal actions could be expansionary, as output growth actually accelerated after these particular fiscal tightenings. Briotti's (2005) survey of empirical work considers a wider set of countries over a wider time period and also finds some evidence that fiscal consolidations can be expansionary. The persistence and composition of the consolidation often matter, with government spending cuts being thought to be pro-growth relative to tax increases.