Spatial interaction models of the gravity type are widely used to describe origin-destination flows. They draw attention to three types of variables to explain variation in spatial interactions across geographic space: variables that characterize the origin region of interaction, variables that...

The railway revolution that swayed through Europe in the nineteenth century left a legacy of unexplored networks. In this paper, we observe a subset of unfinished railways to evaluate the impact of railroads on population growth. Using the random nature of the achieved portions, we compare...