This data shows that nearly all of the world's large urban areas have extensive suburbs of much lower density outside the central cores that are characterized by higher densities, in most cases. Some post-automobile urban areas have virtually no urban cores at all.xxiThese findings are backed by a joint study by UN-Habitat, New York University and the Lincoln Institute of Land Policy on a representative sample of 200 cities across the globe, which established that the average rate of the physical expansion of cities is about one-and-a-half times that of their population growth. By measuring the rate at which cities consume land compared to their rate of population growth, city authorities and decision makers can project demand for public goods and services, identify new areas of growth, and proactively influence sustainable urban development.