2、引力模型是一个基本理论假设，不仅适用于人口流动，也适用于任何具有反距离权重特征的其他要素预测。并且它仅考虑两地距离和相应人口数量，很难说是一个通用或主流的人口流动模型，称其为“框架”或“假设”更好些。原文作者也称“Therefore, the lack of an alternative framework has kept the gravity law as the dominant predictive tool in transport and mobility modelling.”
A universal model for mobility and migration patterns Filippo Simini1,2,3, Marta C. Gonza´lez4, Amos Maritan2 & Albert-La´szlo´ Baraba´si1,5,6
Introduced in its contemporary form in 1946 (ref. 1), but with roots that go back to the eighteenth century2, the gravity law1,3,4 is the prevailing framework with which to predict population movement3,5,6, cargo shipping volume7 and inter-city phone calls8,9, aswell asbilateral trade flows between nations10. Despite its widespread use, it relies on adjustable parameters that vary from region to region and suffers from known analytic inconsistencies. Here we introduce a stochastic process capturing local mobility decisions that helps us analytically derive commuting and mobility fluxes that require as input only information on the population distribution. The resulting radiation model predicts mobility patterns in good agreement with mobility and transport patterns observed in a wide range of phenomena, from long-term migration patterns to communication volume between different regions. Given its parameter-free nature, the model can be applied in areas where we lack previous mobility measurements, significantly improving the predictive accuracy of most of the phenomena affected by mobility and transport processes11–23.
