A Deep Gravity model for mobility flows generation

The movements of individuals within and among cities influence critical aspects of our society, such as well-being, the spreading of epidemics, and the quality of the environment. When information about mobility flows is not available for a particular region of interest, we must rely on mathematical models to generate them. In this I first introduce the Gravity Model, a parametric model that can be used to predict flows among cities. I will show that such model is equivalent to a one layer classifier, i.e. a Perceptron. I will then study and apply a more general and effective model, Deep Gravity, that can generate flow probabilities exploiting many features (e.g., land use, road network, transport, food, health facilities) extracted from voluntary geographic data, and uses deep neural networks to discover non-linear relationships between those features and mobility flows. I will show that Deep Gravity achieves a significant increase in performance, especially in densely populated regions of interest, with respect to the classic gravity model and models that do not use deep neural networks or geographic data.