This paper extends the urban growth model of Duranton and Puga (2022) to explore the impact of cities on local firms and households and the aggregate economy of Germany. We adopt alternative micro-foundations for agglomeration economies and a non-linear specification of human capital...

This paper studies urban sustainability from the perspective ofexternalities. We develop a general spatialequilibrium model of a monocentric city, in which two types ofexternalities occur. On the one hand, pollution inthe industrial centre leads to a spatially differentiateddeterioration of the...

Social interactions are considered pivotal to agglomeration economies. We explore a unique dataset on mobile phone calls to examine how distance and population density shape the structure of social interactions. Exploiting an exogenous change in travel times, we show that distance is highly...

Should constraints on urban expansion be relaxed because of external agglomeration economies? In a system of heterogeneous cities, we demonstrate that second-best land use policy consists of a tax on city creation and a subsidy (tax) on urban development in cities in which the marginal-average...

Beijing has undergone rapid urbanisation from 1950-2010. The main built-up area expanded concentrically from 100 to 1210 km2. Its urban fringe became popular for new developments, some placed haphazardly. The government concentrated efforts in "stopping concentric fringe expansion". E.g. on...