The basic idea, inspired by Head and Mayer (2002), is to calculate
distance between two countries based on bilateral distances between the biggest cities of those
two countries, those inter-city distances being weighted by the share of the city in the overall
country’s population.
这里的意思是用两个国家间最大的城市距离来比较,那么中国用上海这个城市,其它国家用各自的最大城市(经济规模上)或者说经济中心。这样可以吗?求解答!!