The Development of the African System of Cities
研究了撒哈拉以南非洲过去半个世纪的城市人口快速增长，发现城市化并未伴随农业生产力提升和工业化，城市农业就业普遍，高首位度带来问题，二级城市工业化不足，可贸易服务业增长可能预示不同的结构转型路径。
Sub-Saharan Africa has experienced high urban population growth over the past half century, dramatically reshaping the economic and spatial profile of the region. Simultaneously, this process has challenged the conventional view that countries urbanize alongside structural transformation, as urbanization in Africa has occurred despite low productivity gains in agriculture and very limited industrialization. While there are large household income gaps between urban and rural areas that induce migration, most cities have very high agricultural employment, blurring the connection between structural transformation and urbanization. Urban income premiums apply equally to farm and nonfarm families. Looking across the urban hierarchy, we discuss how high urban primacy presents problems for economic growth in Africa, how secondary cities are faltering with a lack of industrialization, and how growth of employment in tradable services may signal a different path to structural transformation.