Festina lente – hurry slowly – is advice we have inherited from the ancient Romans. Western policymakers should now take it to heart. Confronted with huge fiscal deficits, many have concluded that they should hurry fiscal tightening on as fast as possible, in the hope that it will prove expansionary. What are the chances that they will be right? Small, I believe. Moreover, rather better alternatives are on offer. But their drawback is that they are unorthodox: alas, many “sound” people prefer orthodox recessions to unorthodox recoveries.

Why might a sharp structural fiscal tightening promote recovery? As Harvard's Alberto Alesina and Silvia Ardagna note in an influential paper, smaller prospective deficits may improve confidence among consumers and investors, thereby raising consumption and lowering risk-premia in interest rates.* Meanwhile, on the supply side, fiscal tightening may increase supply of labour, capital or entrepreneurship. The broad conclusions of their paper are that fiscal adjustments “based upon spending cuts and no tax increases are more likely to reduce deficits and debt over gross domestic product ratios than those based upon tax increases. In addition, adjustments on the spending side rather than on the tax side are less likely to create recessions.” This line of argument has strengthened the will of George Osborne, the UK's new chancellor of the exchequer.

Is it persuasive? In a word: no. The authors group together data for members of the Organisation for Economic Co-operation and Development between 1970 and 2007. But the impact of fiscal tightening is going to depend on circumstances.