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...

A growing body of evidence suggests that uncertainty is counter cyclical, rising sharply in recessions and falling in booms. But what is the causal relationship between uncertainty and growth? To identify this we construct cross country panel data on stock market levels and volatility as proxies...

We explore the effects of environmental taxes that imprecisely target pollution. A review of actual policies indicates few (if any) examples of a true tax on pollution. More typically, environmental taxes target an input or output that is correlated with pollution. We construct a simple...

We examine next-day newspaper accounts of large daily jumps in 16 national stock markets to assess their proximate cause, clarity as to cause, and the geographic source of the market-moving news. Our sample of 6,200 market jumps yields several findings. First, policy news - mainly associated...

We examine patterns of economic policy uncertainty (EPU) around national elections in 23 countries. Uncertainty shows a clear tendency to rise in the months leading up to elections. Average EPU values are 13% higher in the month of and the month prior to an election than in other months of the...

We argue that social capital as proxied by regional trust and the Rule of Law can improve aggregate productivity through facilitating greater firm decentralization. We collect original data on the decentralization of investment, hiring, production and sales decisions from Corporate Head Quarters...

Cap and trade systems are emerging as the front-running policy choice to address climate change concerns in many countries. One of the apparent attractions of this approach is the ability to achieve hard limits on emissions over a control period. The cost of achieving this certainty on emission...