The gravity of distance: evidence from a trade embargo
利用2017年卡塔尔空域封锁这一准自然实验，研究因航线绕行导致的旅行距离增加对双边贸易的影响，发现进口的距离弹性在-0.3到-0.5之间，修正了以往估计。
Abstract On 5 June 2017, an airspace blockade was imposed on the State of Qatar by Bahrain, Saudi Arabia, United Arab Emirates (neighboring countries), and Egypt. We exploit this exogenous increase in air transportation costs toward non-blockading countries to examine the effect of increased travel distance, due to re-routing, on bilateral trade. Based on a gravity model estimated using a Poisson pseudo-maximum likelihood estimator, we find a distance elasticity of imports between −0.3 and −0.5. Overcoming the limitations of cross-sectional studies and taking advantage of this quasi-natural experiment, our findings are robust and revise downward previous estimates of the distance elasticity.