Commuting with Lost Housing Services as the Opportunity Cost
修改了单中心城市模型，引入雇主控制工作时间、家庭内消费更多住房服务以及土地价格与面积不成比例等假设，解释了美国大都市区中家庭按收入混合、按家庭规模分离的现象。
In American metropolitan areas, households are highly mixed by income with higher average incomes at greater distances from downtown. Also, suburbs attract families with children, while poor households and small households with young heads select sites close to the commercial core. These empirical observations and others are predicted by this standard model of a monocentric city with three major modifications. Time at work is controlled by employers, not employees. Households with more members at home consume in the same house more housing services. Finally, lot prices need not be proportional to area. In the resulting equilibrium, households are mixed by income and separated by family size. This contrasts with classic urban models where households are separated only by their workers' wage rates.