Suburbanization in the USA, 1970–2010
研究1970-2000年美国郊区化现象，通过新方法区分工作地吸引力、居住地吸引力和通勤摩擦三种解释，发现通勤摩擦减少（如高速公路扩张和汽车成本下降）是主因，而工作地和居住地吸引力变化则解释了就业向低密度区转移。
The second half of the 20th century saw large‐scale suburbanization in the USA, with the median share of residents who work in the county where they live falling from 87% to 71% between 1970 and 2000. We introduce a new methodology for discriminating between the three leading explanations for this suburbanization (workplace attractiveness, residence attractiveness and bilateral commuting frictions). This methodology holds in the class of spatial models that are characterized by a structural gravity equation for commuting. We show that the increased openness of counties to commuting is explained mainly by reductions in bilateral commuting frictions, consistent with the expansion of the interstate highway network and the falling real cost of car ownership. We find that changes in workplace attractiveness and residence attractiveness are more important in explaining the observed shift in employment by workplace and employment by residence towards lower densities over time.