法国预测与国际信息中心：重力的变化（英文版）

This paper documents a fundamental problem in applied gravity estimation: the variance of gravity estimates becomes prohibitively large when policy regressors are parse. I define sparse regressors as dummy variables that equal one in fewer than 100 to 500 observations depending on the setting; a common characteristic of trade policies such as free trade agreements. Through Monte Carlo simulations calibrated to match previously established data generating processes in the literature, I demonst