Economic and policy uncertainty: Aggregate export dynamics and the value of agreements
研究了经济与政策不确定性如何通过企业异质性模型影响出口投资，发现贸易协议能缓解不确定性冲击，并用2003-2011年美国企业数据解释了贸易崩溃期间出口增长差异。
We examine the interaction of economic and policy uncertainty in a dynamic, heterogeneous firms model. Uncertainty about foreign income, trade protection, and their interaction dampens export investment. Trade agreements can mitigate uncertainty and the probability of policy uncertainty shocks. We use firm data from 2003–2011 to establish new facts about U.S. export dynamics. These facts include a differentially lower export growth to non-preferential markets driven by the extensive margin at the start of the Great Trade Collapse. The structural model can explain this differential as a consequence of a shock to demand uncertainty. The shock was three times larger for non-preferential markets than preferential ones and it was later reversed, which is consistent with the timing of trade war fears in the crisis.