Population Density and Infrastructure Development

A model is proposed with the following features: (1) there is a publicly accessible transport technology, which is more advanced when there is more specialized labor in it; (2) a high population density facilitates the development of the transport technology; (3) an improved transport technology facilitates a finer division of labor, which in turn increases per capita income. These features are compatible with the phenomena of economic development described by Boserup in 1981. It is also shown that, provided the infrastructure sector can charge the users, and individuals are free to choose jobs, the competitive equilibrium will be Pareto-optimal.