Regulating Urban Sustainability
Cities feature prominently in debates over how to deal with the existential threat of climate change, alternating between the role of potential savior (e.g. Copenhagen or Amsterdam) and prime culprit (e.g. Phoenix or Brisbane). The foundations of the debate on urban sustainability, however, are too often based on research from data-rich regions of the world, such as the United States and Europe. That bias may soon change. Globally available, harmonized datasets are enabling new, robust, comparative analysis of cities. This paper is an effort to begin answering a basic question—how do urban land policies shape sprawl, urban transportation, and greenhouse gas emissions? To assess the relationships between these elements of urban sustainability, we combine high-quality, globally available GIS data on urban footprints, population density, transportation patterns, and carbon emissions with surveys of regulatory processes from the World Bank’s Doing Business project for over 400 cities in nearly 40 countries. The sample contains predominantly middle-income countries, but it is the beginning of research that will eventually cover the entire world.
One set of findings confirms the importance of urban form for carbon dioxide (CO2) emissions. Dense, compact cities with built-up downtowns and shorter roadway segments have lower CO2 emissions per capita. Our findings on the relationship between land regulations and emissions tell a more complicated story. In the global sample of cities, we find that density is associated with more time-consuming regulations, and places with ‘more’ regulations have lower emissions. The fact that these are correlations is fundamental and underscores that regulations are created when density is present. The finding is especially relevant when contrasted against evidence in rich countries that emphasizes how regulations preventing dense urbanization promote sprawl. We also examine the relationship between regulations and informality, finding that cities with ‘more’ regulation do indeed have more slums.
The results highlight the need for a nuanced understanding of the relationships among regulations, urban form, and sustainability. Regulations are necessary for urban density and sustainability to be productive and functional, though in some contexts they are counterproductive and promote sprawl. We propose a global model to frame this idea and argue that finding the right regulatory balance is important, as is understanding where a given city is on this spectrum. As a global research community, we need more and better data to unpack this nuance. This paper’s limitations illustrate that point and establish a framework for assessing relationships among regulations, urban form, and emissions, a surprisingly underemphasized chain in urban research.