Gravity Model of Tourist Flows

The gravity model of tourist flows explains travel between an origin and a destination by analogy to Newton's law of gravitation: bilateral flows increase with the economic 'mass' of both the origin and the destination and decrease with the distance and cost of travel between them. Borrowed from international trade, the model has become a standard tool for analyzing the structural determinants of international tourism, capturing how population, income, distance, common language, shared borders, and historical or cultural ties shape who travels where. Clive Morley, Jaume Rossello, and Maria Santana-Gallego's 2014 Annals of Tourism Research paper grounded the tourism gravity equation in individual utility theory, while the broader trade literature — notably Anderson and van Wincoop's 'multilateral resistance' insight — showed how to specify and estimate it without bias.