On the Internal Structure of Cities
证明了一个环形城市中企业和住宅可任意选址的对称均衡存在性，并分析了通勤成本与集聚效益如何决定城市土地利用形态。
We prove the existence of a symmetric equilibrium in a circular city in which businesses and housing can both be located anywhere in the city. In this equilibrium, firms balance the external benefits from locating near other producers against the costs of longer commutes for workers. An equilibrium city need not take the form of a central business district surrounded by a residential area. We propose a general algorithm for constructing equilibria, and use it to study the way land use is affected by changes in the model's underlying parameters.