This review article tries to answer four questions: (i) what are the stylized facts about uncertainty over time; (ii) why does uncertainty vary; (iii) do fluctuations in uncertainty matter; and (iv) did higher uncertainty worsen the Great Recession of 2007-2009? On the first question both macro...

Many commentators argue that uncertainty about tax, spending, monetary and regulatory policy slowed the recovery from the 2007-2009 recession. To investigate this we develop a new index of economic policy uncertainty (EPU), built on three components: the frequency of newspaper references to...