PROPERTIES OF MAXIMUM LIKELIHOOD ESTIMATES OF GRAVITY MODEL PARAMETERS*
给出了引力模型参数估计协方差矩阵的简单公式，并研究了参数估计的偏差、稳健性以及Sen(1986)估计方法的收敛性。
ABSTRACT. We give a very simple formula for obtaining covariance matrices of gravity model parameter estimates. We investigate bias and robustness of parameter estimates, as well as the convergence of the procedure given in Sen (1986) for obtaining these estimates.