Distance, Time, and Specialization: Lean Retailing in General Equilibrium
证明运输时间影响全球专业化分工：需要及时交付的产品会在靠近最终需求地生产，导致当地工资更高。利用美国服装进口数据，发现对及时性要求高的产品越来越从邻近国家进口。
Transport time increases with distance traveled, and time is valuable. We show the implications of these facts for global specialization and trade: products where timely delivery is important will be produced near the source of final demand, where wages will be higher as a result. In the model, timely delivery is important because it allows retailers to respond to final demand fluctuations without holding costly inventories, and timely delivery is possible only from nearby locations. Using a unique dataset that allows us to measure the retail demand for timely delivery, we show that the sources of U.S. apparel imports have shifted in the way predicted by the model, with products for which timeliness matters increasingly imported from nearby countries.