More Urban Constructions for Whom? Drivers of Urban Built-Up Expansion Across the World from 1990 to 2015

International audienceSince the 1990s, the conversion of land for urban use has never been more intense. Occurring under all latitudes, transcending the economic disparities as well as the political regimes, urban built-up expansion appears very much articulated to the global financial turn, which occurred after the progressive destatization of the money creation, which accelerated and globalized after the debt crisis of the 1980s. Using the Global Human Settlement Layer dataset on the degree of urbanization, we can assess that, worldwide, the built-up surface expanded by 243,000 km2 between 1990 and 2015 and the average urban density has declined slightly from 2775 inhabitants per km2 to 2756. After describing the national level dataset used and our methodology, we expose the regional nuances in the global built-up spreading and their relations to population growth. Then in a third section, we correlate those national trends with a set of significant economic indicators. We articulate it also to the individualization and progress of housing condition. Population growth remains the dominant factor determining urban built-up spread, but countries differ. Built-up growth did not respond linearly to the final demand for housing and therefore to demographic pressure. Building is a material good whose value is also interdependent with economic growth. The universal relationship between size and density specific to scaling laws is verified once again in the case of cities. However, economic density or concentration of wealth tends to take precedence over population mass to explain urban built-up expansion