Agglomeration externalities and urban growth controls
研究在异质性城市系统中，如何通过次优土地利用政策（限制城市创建、对边际-平均生产率差距大的城市补贴开发）来更好地利用集聚经济，并比较了竞争性城市开发商的结果。
How can land use policy enhance the exploitation of external urban agglomeration economies? In a system of heterogeneous cities, we show that the second-best land use policy constrains city creation, while subsidizing (taxing) urban development in cities in which the marginal-average productivity gap is above (below) average. This policy cannot be decentralized to competitive urban developers, yet competition among urban developers does result in a lower-best outcome in which development is subsidized everywhere if city creation is unconstrained. A numerical application indicates that a substantial share of the welfare gains from implementing a second-best land use policy may then still be attained, although the aggregate amount of land in urban use is considerably larger.