Population Dynamics, Urbanisation without Growth, and the Rise of Megacities
研究了发展中国家尤其是撒哈拉以南非洲地区城市化未能带来预期经济增长的现象，通过动态模型和坦桑尼亚等数据解释了无增长城市化与贫困巨型城市崛起的成因。
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 from Tanzania.