Unpacking Aggregate Welfare in a Spatial Economy
研究在空间均衡模型中，区域生产率冲击或交通基础设施改善如何影响总体福利，分解出技术、空间边际效用分散、财政外部性、技术外部性和再分配五个因素，并应用于美国高速公路网络改善的福利评估。
Abstract How do regional productivity shocks or transportation infrastructure improvements affect aggregate welfare? In a general class of spatial equilibrium models, we provide a formula for aggregate welfare changes, decomposed into terms associated with (i) technology [Fogel (1964), Railroads and American Economic Growth (Baltimore: Johns Hopkins Press), Hulten (1978) “Growth Accounting with Intermediate Inputs”, The Review of Economic Studies, 45, 511–518], (ii) spatial dispersion of marginal utility, (iii) fiscal externalities, (iv) technological externalities, and (v) redistribution. We further use this decomposition to derive a general formula for optimal spatial transfers and show that, whenever optimal transfers are in place, the technology term alone captures the aggregate welfare effects of technological shocks. We apply our framework to study welfare gains from improving the US highway network. We find that changes in the spatial dispersion of marginal utility are as important as technological externalities in accounting for the deviations from the Fogel-Hulten benchmark to assess welfare gains.