To date, comparative analyses of human migration and population structure have focused on a single explanatory variable—geographic distance. These models are expanded here by extensions of the gravity model developed by geographers. This model considers the number of migrants between populations to be a function of geographic distance and the population sizes of recipient and source populations. The generalized model allows detection of both negative size dependence and positive size dependence. Hypothetical examples are used to illustrate interpretations of the coefficients derived from the model. Applications of the model are presented using data from three culturally and ecologically distinct populations: horticultural (New Guinea tribes), continental agricultural (historical Massachusetts), and island agricultural (historical Aland Islands). For all samples, the gravity model provides a better fit than simple distance decay models. The results suggest that the most common pattern of migration is from small to large populations.
Relethford, John H.
"A Gravity Model of Human Population Structure,"
5, Article 12.
Available at: https://digitalcommons.wayne.edu/humbiol/vol58/iss5/12