We present a simple model to show that urban concentration of developing countries reduces with foreign direct investment (FDI) if the FDI is attracted to their relatively "remote" regions; otherwise, the urban concentration increases. To reduce urban concentration, this paper suggests that developing countries better carries out some favorable policies to improve their "remote" regions' infrastructure that makes them be more freely accessible to international markets. Thus, the FDI raises demand for local workers and then attracts migration from incumbent megacities, leading to lower urban concentration. The declining urban concentration increases labor supply by reducing commuting costs, hereby improving welfare.
我們建立一簡單的模擬,以說明開發中國家的農村城鎮化時的大城市病會隨著開放外國投資而減少,只要這些外國投資是被導引到相對「偏遠」地區。否則,大城市病會隨著開放外國投資而更嚴重。為了避免大城市病裏常有的高污染和擁塞,本文建議,一個開發中國家在貿易自由化之際,政府應先投資良好的交通基礎建設將外資吸引到其「偏遠」地區。如此,外資投資可幫助減少其大城市病;否則,外資反而會益增其大城市病。因此,本文建議,為了成功吸引外資到其「偏遠」地區,開發中國家可在當地建立經濟特區或工業園區,同時也提供優惠政策並在此投資基礎建設使之更好的連結國際市場。這些經濟特區會因外資進駐而帶來工作機會,幫助分流商業大都會的人口,因而流入減少大城市病。另外,本文也認為,當大城市病減少時,其因而減少的通勤擁塞會釋放人力資源,從而增加該國更多的生產和福利。