Expert panel discussion: Methods, experiments, and data
This session discussed methodological issues for conducting studies related to cities and urban development. Nathaniel Baum-Snow (Brown University) said that a key constraint for research on cities is the difficulty in finding appropriate control groups for comparison, and to scale-up interventions in a manner that provides rigorous results of impact. This is because in cities there are many linkages between the housing market, labour market, transport system etc. He said that one way to push forward is to generate more data on households living in cities.
Marcel Fafchamps (Stanford University) spoke about the issues of rapid urbanisation in Africa. According to UN estimates, the population of Africa is expected to reach 4 billion by 2100 and a large part of it will be living in urban areas. Economists must conduct new research on cities to contribute to improving the spatial efficiency of Africa’s urbanization. He presented existing theory on understanding the economy of cities and their economic relationship with the surrounding countryside.
Stephen Redding (Princeton University) promoted the use of quantitative spatial models, which have made a lot of progress in the past few years. He is using these to estimate commuting, migration and local employment elasticities. His research aims to assess the impact of local changes in the economic environment and their ability to attract factors of production – especially labour. He said that commuting of workers between locations is important and this spatial aspect must be accounted for while estimating impacts of interventions on the labour market.