Using U.S. Census microdata, the authors show that, on average, workers change occupation and industry less in more densely populated areas. The result is robust to standard demographic controls, as well as to including aggregate measures of human capital and sectoral mix. Analysis of the...

We contrast evidence of urban path dependence with efforts to analyze calibrated models of city sizes. Recent evidence of persistent city sizes following the obsolescence of historical advantages suggests that path dependence cannot be understood as the medium-run effect of legacy capital but...

We examine portage sites in the U.S. South, Mid-Atlantic, and Midwest, including those on the fall line, a geomorphologic feature in the southeastern U.S. marking the final rapids on rivers before the ocean. Historically, waterborne transport of goods required portage around the falls at these...

Many cities in North America formed at obstacles to water navigation, where continued transport required overland hauling or portage. Portage sites attracted commerce and supporting services, and places where the falls provided water power attracted manufacturing during early industrialization....

The authors examine portage sites in the U.S. South, Mid-Atlantic, and Midwest, including those on the fall line, a geomorphological feature in the southeastern U.S. marking the final rapids on rivers before the ocean. Historically, waterborne transport of goods required portage around the falls...

Workers change occupation and industry less often in more densely populated areas, a relationship that had not been previously reported. This reduced-form result is robust to standard demographic controls, as well as to including aggregate measures of human capital and sectoral mix. Analysis of...

This paper presents new, computationally efficient algorithms for solution and estimation of nonlinear dynamic rational expectations models. The innovations in the algorithms are as follows: (1) The entire solution path is obtained simultaneously by taking a small number of Newton steps, using...

Where does adaptation to innovation take place? The supply of educated workers and local industry structure matter for the subsequent location of new work–that is, new types of labor-market activities that closely follow innovation. Using census 2000 microdata, the author shows that regions...

Where does adaptation to innovation take place? The author presents evidence on the role of agglomeration economies in the application of new knowledge to production. All else equal, workers are more likely to be observed in new work in locations that are initially dense in both college...