The Average and Heterogeneous Effects of Transportation Investments: Evidence from Sub-Saharan Africa 1960-2010
Previous work on transportation investments has focused on average impacts in high- and middle-income countries. We estimate average and heterogeneous effects in a poor continent, Africa, using roads and cities data spanning 50 years in 39 countries. Using changes in market access due to distant road construction as a source of exogenous variation, we estimate a 30-year elasticity of city population with respect to market access of about 0.08-0.13. Our results suggest that this elasticity is stronger for small and remote cities, and weaker in politically favored and agriculturally suitable areas. Access to foreign cities besides international ports matters little. Additional evidence points suggestively to rural-urban migration as the primary source of this population increase, though we cannot fully rule out natural increase or reallocation across cities.
We thank Simon Alder, Treb Allen, Pol Antras, Nathaniel Baum-Snow, Kristian Behrens, Gharad Bryan, Kerem Cosar, Victor Couture, Dave Donaldson, Esther Duflo, Gilles Duranton, Benjamin Faber, Edward Glaeser, Vernon Henderson, Eoin McGuirk, Melanie Morten, Paul Novosad, Elias Papaioannou, Harris Selod, Matthew Turner, Anthony Venables, Leonard Wantchekon and various seminar and conference audiences for helpful comments, and Yasmin Abisourour, Karen Chen, Rose Choi, Taher Elsheikh, Yury Higuchi, Erin McDevitt, and Emily Ryon for research assistance. We are grateful to Uwe Deichmann and Siobhan Murray for sharing their roads data, Francois Moriconi-Ebrard for help with data collection, and Delilah Maloney and Durwood Marshall for programming advice. We thank the World Bank's Strategic Research Program on Transport Policies for Sustainable and Inclusive Growth, the Elliott School of International Affairs and the Institute for International Economic Policy at GWU, and the Global Research Program on Spatial Development of Cities, funded by the Multi Donor Trust Fund on Sustainable Urbanization of the World Bank and supported by the UK Department for International Development, for financial assistance. The views expressed herein are those of the authors and do not necessarily reflect the views of the National Bureau of Economic Research.
In the past three years, I have received income and/or fees summing to amounts in excess of $10,000 from the following various parties for different research projects:
- The United Nations
- The World Bank
- The International Monetary Fund
It is my belief that these organizations do not have a financial, ideological, or political interest in the subject matter of this paper, but these institutions work in the field of international development policy, which is intrinsically political.Adam Storeygard
In the past three years I have received significant research funding from the World Bank, the European Union, and the UK Department for International Development.