David Castells-Quintana (p), Hugh Wenban-Smith

Lewis Dijkstra

That urbanisation in many developing countries, especially in Sub-Saharan Africa, is not delivering the kind of benefits that might be expected in the light of experience elsewhere in the world is now widely acknowledged. This urbanisation without growth has been the focus of recent research in both the development and urban economics literature. In this paper, we focus on demographic factors and develop a simple dynamic model to describe internal migrations, the evolution of the urban rate and total productivity, and how these are affected by population growth and investments in urban infrastructure. Our model can predict basic trends in the data, including urbanisation without growth and the rise of (poor) megacities. We complement the model with empirical evidence using (i) international cross-country panel data; and (ii) regional data for Tanzania.

Paolo Veneri (p), Ana Moreno Monroy

David Castells-Quintana

This paper provides a description of suburbanisation trends in different areas of the world, by relying on a consistent definition of urban economic agglomerations applied in different regions of the world. By using the available geospatial dataset designating the borders of functional urban areas (FUAs) – i.e. urban agglomerations composed of a dense and large urban space (urban core) and a surrounding commuting zone (hinterland) – across the OECD together with the newly defined FUAs in middle and high income non-OECD countries, the paper analyses whether there are consistent and predictable global suburbanisation trends that can be linked to city sizes and levels of development (Cheshire, 1999; Veneri, 2017). The recent availability of several global geo-spatial population datasets at a high level of resolution makes it possible to build indicators characterising urban hinterlands and compare them with urban cores in terms of population levels, growth and density, land use, demographic composition and level of economic activity. By means of international comparison, the questions addressed in the paper will include a) whether low density areas within functional urban areas growing more rapidly than high density areas; b) for what kind of cities suburbanisation has been accompanied by densification; and c) whether suburbanisation patterns can be inferred from city size, controlling for other urban characteristics.

Susanne Frick, Andrés Rodríguez-Pose (p)

Paolo Veneri

Do changes in urban structure shape economic growth? For the majority of the economics literature, the presence of large cities and urban concentration are deemed to lead to greater national economic growth. However, the arguments for this link have often been built on thin ice. This paper revisits whether (1) the evolution of urban concentration in developed and developing around the world has waxed or waned over the last three decades and (2) the extent to which the degree of urban concentration affects national economic growth. It is found that urban concentration levels have on average decreased or remained stable (depending on indicator). However, these averages camouflage widely diverging trends across countries. Moreover and in contrast to previous analyses that generally underscore the benefits of urban concentration especially at low levels of economic development, there is no uniform relationship between urban concentration and growth. Urban concentration has been beneficial for growth in high-income countries, while this effect does not hold for developing ones.

Valentina Cattivelli (p)

Andrés Rodríguez-Pose

'see extended abstract'

Lewis Dijkstra (p)

Valentina Cattivelli

A global definition of cities and rural areas does not yet exist. This hampers international comparisons and the capacity to learn from good practices in other countries. The UN Sustainable Development Goals include a specific goal dedicated to cities and includes a number of indicators that have to be measured per city including access to public transport, access to green space, changes in population and built-up area. These indicators are highly sensitive to where the boundary of a city is drawn. This makes the need for a global definition a city even more urgent.

At the Habitat III conference in Quito, the European Commission, the OECD and the World Bank committed to developing a global, people-based definition of cities and settlements to facilitate international comparisons and cross border learning. The FAO has joined this commitment in 2017.

This presentation will show the results of applying the degree of urbanisation to the globe. It will discuss how these results differ from the data collected by the UN Statistical Division based on national definitions and the reasons for the sometimes large differences. As part of this work, a number of pilot countries have tested this definition and compared it to their national definitions. This presentation will summarise the main conclusions of this work. Finally, it will sketch out the next steps towards the presentation in March 2019 to the UN Statistical Commission.