摘要：This paper presents new evidence on urbanization using sub-county data for the
United States from 1880-2000 and municipality data for Brazil from 1970-2000. We
show that the two central stylized features of population growth for cities –
Gibrat’s Law and a stable population distribution - are strongly rejected when
both rural and urban areas are considered. Population growth exhibits a U-shaped
relationship with initial population density, and only becomes uncorrelated with
initial population density at the high densities found in predominantly urban
areas. We provide evidence that the explanation for these patterns lies in
different employment growth dynamics in the agricultural and non-agricultural
sectors and the process of structural transformation away from the agricultural
sector.
关键词：urbanisation, economic development, urban population, rural population
