Search Results
Working Paper
Portage: path dependence and increasing returns in U.S. history
The authors 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 points, while some falls provided water power during early industrialization. These factors attracted commerce and manufacturing. Although these original advantages have long since been made obsolete, the authors document the continuing-and even increasing-importance of these portage sites over ...
Working Paper
Thick-market effects and churning in the labor market: evidence from U.S. cities
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 displaced worker surveys shows that this effect is present in cases of involuntary separation as well. On the other hand, the authors actually find the opposite result (higher rates of occupational and industrial switching) for the subsample of younger workers. These results provide evidence in favor of ...
Journal Article
Understanding Gentrification’s Causes
What do three centuries of Philadelphia history tell us about today?s changing neighborhoods?
Journal Article
The Costs and Benefits of Fixing Downtown Freeways
Urban freeways spurred our suburban boom. Can burying them do the same for the urban core?
Working Paper
Natural Amenities, Neighborhood Dynamics, and Persistence in the Spatial Distribution of Income
We present theory and evidence highlighting the role of natural amenities in neighborhood dynamics, suburbanization, and variation across cities in the persistence of the spatial distribution of income. Our model generates three predictions that we confirm using a novel database of consistent-boundary neighborhoods in U.S. metropolitan areas, 1880{2010, and spatial data for natural features such as coastlines and hills. First, persistent natural amenities anchor neighborhoods to high incomes over time. Second, naturally heterogeneous cities exhibit persistent spatial distributions of income. ...
Working Paper
Portage and path dependence
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 at these points, while some falls provided water power during early industrialization. These factors attracted commerce and manufacturing. Although these original advantages have long since been made obsolete, the authors document the continuing importance of these portage sites over time. They ...
Journal Article
Urban productivity advantages from job search and matching
Densely populated areas tend to be more productive. Of course, the cost of living and producing in these locations is higher because congestion raises the cost of scarce fixed resources such as land. But despite the higher prices, many people and businesses continue to live and work in these areas. Why? One explanation is that these locations have natural advantages, such as proximity to a river. Another says that this concentration of households and businesses by itself generates productivity advantages in the form of agglomeration economies. In studying these agglomeration economies, ...
Working Paper
Strong Spatial Spillovers Determine Neighborhood Shape and Neighborhood Change
This paper explores how spatial spillovers define neighborhoods and drive neighborhood change through a stylized computable equilibrium model of income-based residential sorting. We find three main results. First, stronger spillovers create larger, more distinct neighborhood clusters even when the spatial scope of externalities is small. Second, spillovers make neighborhoods resistant to small change but also susceptible to rapid shifts between equilibrium states. Third, stronger spillovers concentrate change at cluster boundaries and isolated locations rather than neighborhood interiors. ...
Working Paper
What Future for History Dependence in Spatial Economics?
History (sometimes) matters for the location and sizes of cities and neighborhood segregation patterns within cities. Together with evidence on rapid neighborhood change and self-fulfilling expectations, this implies that nature might not completely determine the spatial structure of the economy. Instead, the spatial economy might be characterized by multiple equilibria or multiple steady-state equilibrium paths, where history and expectations can play decisive roles. Better evidence on the conditions under which history matters can help improve theory and policy analysis.
Working Paper
The Paper Trail of Knowledge Spillovers: Evidence from Patent Interferences [REVISED]
REVISED 9/2019: We show evidence of localized knowledge spillovers using a new database of multiple invention from U.S. patent interferences terminated between 1998 and 2014. Patent interferences resulted when two or more independent parties simultaneously submitted identical claims of invention to the U.S. Patent Office. Following the idea that inventors of identical inventions share common knowledge inputs, interferences provide a new method for measuring spillovers of tacit knowledge compared with existing (and noisy) measures such as citation links. Using matched pairs of inventors to ...