The size of the fiscal policy multiplier – and thus the impact of austerity on GDP – has been a contentious issue since the crisis started. The IMF recently revived the debate by suggesting that the multiplier is much higher than previously thought in the current policy environment. This column discusses independent empirical research that confirms the IMF’s view – the authors’ estimate of the multiplier is in the range of 1.6.

Few things divide the economics profession more than this question: How much economic activity does $1 of government spending generate? This column provides a new angle. Looking at local councils in Italy between 1990 and 1999, it examines variation in budgets due to the removal of funds by central government if mafia involvement is suspected. It finds that the fiscal multiplier starts at 1.4 and rises to 2.0.

The return from a fiscal stimulus – the fiscal multiplier – remains one of the most controversial topics in economics today. This column considers the influence of expectations, of variation in recessions and expansions, and of different components of government spending. It finds that the size of the multiplier varies considerably over the business cycle: between 0 and 0.5 in expansions and between 1 and 1.5 in recessions.

How much stimulus does spending provide? This column says that fiscal multipliers are much weaker in countries that have high debt, lower income, flexible exchange rates, and greater international openness. Policymakers should consider these characteristics when evaluating the benefits of any fiscal stimulus package.

US economic advisers called for aggressive fiscal stimulus, and some support further measures. But many macroeconomists are not so sure. This column analyses fiscal stimulus using a New Keynesian model that exemplifies contemporary academic thinking on the subject. It says that the spending multiplier is much lower than the Obama administration’s estimates – government spending may quickly crowd out private consumption and investment.

Policymakers have committed substantial sums to addressing the global recession and the global financial crisis, but there is real doubt about their effectiveness. This column explains why the fiscal stimulus might fail.