The long-term trends of urbanization suggest: not only have more cities formed, but the leading metropolises have grown larger, with a number of peripheral subcenters developing over time. Conventional models of urban growth are limited, in that commuting cost and congestion eventually result in...

This paper demonstrates that a pollution tax with a fixed cost component capturing an “ambient tax” may lead, by itself, to stratification between clean and dirty firms without heterogeneous preferences or increasing returns. We construct a simple model with two locations and two industries...