Railways and cities in India
利用殖民地印度城市人口新数据集，研究发现1881-1931年间铁路网络扩大了城市规模，且效果主要由初始规模小且孤立的城市驱动。
Using a new dataset on city populations in colonial India, we show that the railroad network increased city size in the period 1881 to 1931. Our baseline estimation approach includes fixed effects for city and year, and we construct instrumental variables for railroad proximity based on distance from a least cost path spanning cities that existed prior to the start of railroad construction. Cities that increased market access due to the railroad grew. The small and heterogeneous effects we find are driven largely by cities that were initially small and isolated.