A METHOD OF FITTING THE GRAVITY MODEL BASED ON THE POISSON DISTRIBUTION*
提出一种将交互变量视为离散概率过程结果的新方法，用于拟合引力模型，尤其适用于少量流动数据（如人口迁移）的分析。
"In this paper, [the authors] suggest an alternative method for fitting the gravity model. In this method, the interaction variable is treated as the outcome of a discrete probability process, whose mean is a function of the size and distance variables. This treatment seems appropriate when the dependent variable represents a count of the number of items (people, vehicles, shipments) moving from one place to another. It would seem to have special advantages where there are some pairs of places between which few items move. The argument will be illustrated with reference to data on the numbers of migrants moving in 1970-1971 between pairs of the 126 labor market areas defined for Great Britain...."