And once in power, notes Peter Mair of the European University Institute in Florence, governments lose popularity more quickly, not least because they are constrained by decisions taken in Brussels.

ECONOMIST: Charlemagne

Elena Carletti, professor of economics at the European University Institute in Florence, agrees that ministers have more to do.

ECONOMIST: Italy��s troubled economy

This question led to my first big book, Mountains of Debt (Oxford University Press), which compared the U.S. to Victorian Britain and Renaissance Florence, the other rich, powerful, debt-plagued cases.

FORBES: An Economist Shares His Thoughts on Wine