Suburbanization and transportation in European cities
研究了高速公路和铁路建设是否导致欧洲城市人口郊区化，利用1961-2011年29国579个城市的数据，发现高速公路是郊区化的原因，而铁路没有影响。
Abstract We study whether highway and railroad improvements cause population suburbanization in Europe’s cities. We construct a unique population and transportation dataset covering 579 cities from 29 European countries for the period 1961–2011. In order to make a causal inference, we rely on historical instruments. Our average results indicate that highways, but not railroads, were responsible for the suburbanization process: each additional highway ray decreased the share of the central city population by 5 percentage points, whereas new railroads had no impact. The heterogeneity analyses provide evidence of different patterns based on the time of the investment, the city’s size and density, and its geographical location.