A first-of-its-kind World Bank analysis, of the shape and growth of nearly 10,000 cities between 1990 and 2015, finds that the most successful urban areas are those that connect their growth to economic demand and then support this with comprehensive plans, policies and investments that help avoid uncontrolled sprawl.
The new report, Pancakes to Pyramids – City Form for Sustainable Growth, analyzes the dynamic, two-way relationship between a city’s economic growth and the floor space available to residents and businesses. It finds that a city is most likely to be its best version when its shape is driven by economic fundamentals and a conducive policy environment – namely, a robust job market, flexible building regulations, dependable public transit and access to essential services, public spaces, and cultural amenities.
Ultimately, getting livable space right, hinges on how a city manages its growth as populations and incomes increase, factoring in three dimensions of expansion – horizontal, vertical or within existing spaces (known as infill), the report finds. This will be key as cities, on the frontlines of the COVID-19 crisis, begin planning for a long-term, resilient, and inclusive recovery.
“Cities are at the frontier of development; they are where people go to chase their dreams of a better life for themselves and their families,” said Juergen Voegele, Vice President for Sustainable Development, World Bank. “This report helps us understand why a city grows outward, inward or up. As we support countries with their COVID-19 recovery efforts, this will also help us reflect on what makes a city livable and remind us that well-planned urban growth is good for both people and planet.”
In the average Sub-Saharan African city, 60 percent of the population lives in slums—a much larger share than the 34 percent average in cities in developing countries. The lack of floor space takes a severe toll on livability—with major consequences in times of pandemics like COVID-19. Many South Asian cities face similar issues.
Horizontal growth is inevitable for most cities. People will continue to migrate to urban areas for opportunities and a better quality of life, so it is crucial for cities to plan for this trend. As urban populations grow, one way to create more space per inhabitant is by building up instead of out. This could also help reduce crowding, discourage long commutes, draw more people to public transit and drive down greenhouse gas emissions. But building tall, or accommodating more people in a city, is dependent on economic demand and the business environment as it requires better technology, large investments, and higher returns on capital.
“Understanding the multiple drivers of city growth—a precondition for livable density in cities—can help city leaders focus on the right policy actions,” said Somik Lall, co-author of the report. “If managed well, cities that take a more pyramid-like shape can provide an impetus to accelerate sustainable development by getting people out of cars, cutting commute times, and limiting greenhouse gas emissions.”
Today, around 55 percent of the world lives in urban areas. By 2050, this number is projected to surpass two-thirds of the global population, with much of the new urbanization happening in Sub-Saharan Africa and South Asia. While such growth signals opportunities and better livelihoods for millions of people, it also puts immense strain on cities, especially in countries that contend with low incomes and weak institutional and fiscal capabilities.
By describing how economic productivity shapes decisions by households and firms to locate in cities, and how the quantity and spatial distribution of urban floor space respond to these changes in demand, the report aims to help decision makers sort through competing legal and regulatory approaches, evaluate their investments in infrastructure, and mobilize finance for durable urban investments, particularly for essential services such as transport, water provision, solid waste management, and sewage removal and treatment.