Working Paper: NBER ID: w27670
Authors: Remi Jedwab; Adam Storeygard
Abstract: 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.
Keywords: Transportation Investments; Market Access; City Population Growth; Sub-Saharan Africa
JEL Codes: F15; F16; O18; O20; R11; R12; R4
Edges that are evidenced by causal inference methods are in orange, and the rest are in light blue.
| Cause | Effect |
|---|---|
| City population growth (R23) | Urbanization dynamics in Sub-Saharan Africa (R23) |
| Market access (L17) | City population growth (R23) |
| Nonlocal road changes (R42) | Market access (L17) |
| Market access (L17) | Rural-to-urban migration (R23) |
| Market access (L17) | Population growth in small and remote cities (R23) |
| Market access (L17) | City population elasticities in rural areas (R23) |
| Market access (L17) | City population elasticities in cities with less favorable agricultural conditions (R11) |