Urban interactions and spatial structure
构建了一个内生空间互动模型，分析个体选择特定地点互动的行为，发现市场均衡无法达到最优，而交通补贴能实现最优，但建设补贴只能达到次优，开发商因无法控制城市面积而无法实现效率。
This article specifies and solves a model of endogenous spatial interactions where agents choose to visit a particular location to interact with others. Equilibrium fails to achieve first-best levels of visits and population density. A construction subsidy can restore second-best efficiency, but not first-best because it does not operate on the visit margin directly. A transportation subsidy can achieve first best. This result--which contrasts with earlier work--comes from treating interaction as a choice variable, rather than focusing on population density, a correlate. Developers are unable to implement even second-best efficiency because of their limited control over a city's land area. Copyright 2007, Oxford University Press.