Uncertainty and the Great Recession
研究识别六种不确定性指标的外生变化，量化其对美国GDP和失业率的影响，发现不确定性仅能解释大衰退期间GDP下降的10%和失业率上升的0.6个百分点。
Abstract Has heightened uncertainty been a major contributor to the Great Recession and the slow recovery in the United States? To answer this question, we identify exogenous changes in six uncertainty proxies and quantify their contributions to GDP growth and the unemployment rate. The answer is no. In total we find that increased macroeconomic and financial uncertainty can explain up to 10% of the drop in GDP at the height of the recession and up to 0.6 percentage points of the increased unemployment rates in 2009 through 2011. Our calculations further suggest that only a minor part of the rise in popular uncertainty measures during the Great Recession was driven by exogenous uncertainty shocks.