Data

This project repository contains the scripts to delineate urban areas using the methodology developed in Combes et al. (2021) as well as some recent developments including a much more scalable and computationally efficient implementation. These methods have since been used by the Banque de France and the World Bank, among others, to delineate urban areas in a large number of countries, using population and building densities.

This project computes historical boundaries of French communes and arrondissements for every year during the period 1793 - 2006. The resulting geometries closely approximate the borders depicted on historical maps, while remaining fully compatible with current projections. The numerous records of the Cassini project contain the disaggregated administrative changes for every commune that existed during this period. This information is collected automatically to track the administrative status of every record at any point in time. Existing records are then matched to current geometries and processed to compute the most precise geometries using the information available. 

The increasing availability of large-scale and open databases offers a strong potential for original economic analysis. OpenStreetMap is a geographical database of the world containing a wide array of public spatial datasets and user-contributed information, harmonised and available through a single platform. Such sources can be used to collect disaggregated data for economic analysis on a large scale. Possible operations include geocoding, the computation of accessibility measures or the collection of city-specific data on amenities, among others.