Working papers

 

The productivity advantages of large cities: Distinguishing agglomeration from firm selection (with Pierre-Philippe Combes, Laurent Gobillon, Diego Puga, and Sébastien Roux)

The effects of land transfer taxes on real estate markets: Evidence from a natural experiment in Toronto (with Benjamin Dachis and Matt Turner)

The Fundamental Law of Road Congestion: Evidence from US cities  (with Matt Turner)

 

Urban growth and transportation (with Matt Turner)

 

Assessing the effects of local taxation using microgeographic data (with  Henry Overman and Laurent Gobillon)

 

Is the division of labour limited by the extent of the market? Evidence from French cities (with Hubert Jayet)

  

California Dreamin’: The feeble case for cluster policies

 


Forthcoming papers

 

Estimating agglomeration economies with history, geology, and worker effects (with Pierre-Philippe Combes, Laurent Gobillon, and Sébastien Roux)

Chapter forthcoming in The Economics of Agglomeration, edited by Ed Glaeser

 

The Economics of Clusters: Evidence from France (with Philippe Martin, Thierry Mayer, and Florian Mayneris)

Book forthcoming at Oxford University Press

 

Urban Growth: Trends vs. Noise

Studia Regionalia, forthcoming

 

Innovation in cities: classical and random urban growth models

Chapter forthcoming in Handbook of Research on Innovation and Entrepreneurship, Edward Elgar, forthcoming (edited by David Audretsch, Oliver Falck, and Stephan Heblich).


The productivity advantages of large cities: Distinguishing agglomeration from firm selection (with Pierre-Philippe Combes, Laurent Gobillon, Diego Puga, and Sébastien Roux) (.pdf)

Firms are more productive on average in larger cities. Two explanations have been offered: agglomeration economies (larger cities promote interactions that increase productivity) and firm selection (larger cities toughen competition allowing only the most productive to survive). To distinguish between them, we nest a generalised version of a seminal firm selection model and a standard model of agglomeration. Stronger selection in larger cities left-truncates the productivity distribution whereas stronger agglomeration right-shifts and dilates the distribution. We assess the relative importance of agglomeration and firm selection using French establishment-level data and a new quantile approach. Spatial productivity differences in France are mostly explained by agglomeration.

 

The effects of land transfer taxes on real estate markets: Evidence from a natural experiment in Toronto (with Benjamin Dachis and Matt Turner) (.pdf)

Taxes levied on the sale or purchase of real estate are pervasive but little studied. By exploiting a natural experiment arising from Toronto’s imposition of a Land Transfer Tax (LTT) in early 2008, we estimate the impact of real estate transfer taxes on the market for single family homes. Our data show that Toronto’s 1.1% tax caused a 15% decline in the number of sales and a decline in housing prices about equal to the tax. Relative to an equivalent property tax, the associated welfare loss is substantial, about 1$ for every 8$ in tax revenue. The magnitude of this welfare loss is comparable to those associated with better known interventions in the housing market. Unlike many possible tax reforms, eliminating existing LTTs in favor of revenue equivalent property taxes appears straightforward.

Media coverage (partial): Globe and Mail, Dec 10, 2008, Globe and Mail, Dec 9, 2008, Toronto Star, December 10, 2008, Vancouver Sun, December 10, 2008.

 

 

The Fundamental Law of Road Congestion: Evidence from US cities (with Matt Turner) (Main paper .pdf Technical Appendix .pdf)

We investigate the relationship between interstate highways and highway vehicle kilometers traveled (VKT) in us cities. We find that VKT increases proportionately to highways and identify three important sources for this extra VKT: an increase in driving by current residents; an increase in transportation intensive production activity; and an inflow of new residents. The provision of public transportation has no impact on VKT. We also estimate the aggregate city level demand for VKT and find it to be very elastic. We conclude that an increased provision of roads or public transit is unlikely to relieve congestion and that the current provision of roads exceeds the optimum given the absence of congestion pricing.

 

Estimating agglomeration economies with history, geology, and worker effects (with Pierre-Philippe Combes, Laurent Gobillon, and Sébastien Roux) (.pdf)

 

Does productivity increase with density? We revisit the issue using French wage and TFP data. To deal with the ‘endogenous quantity of labour’ bias (i.e., urban agglomeration is consequence of high local productivity rather than a cause), we take an instrumental variable approach and introduce a new set of geological instruments in addition to standard historical instruments. To deal with the ‘endogenous quality of labour’ bias (i.e., cities attract skilled workers so that the effects of skills and urban agglomeration are confounded), we take a worker fixed-effect approach with wage data. We find modest evidence about the endogenous quantity of labour bias and both sets of instruments give a similar answer. We find that the endogenous quality of labour bias is quantitatively more important.

 

 

Urban growth and transportation (with Matt Turner) (.pdf)

 

We estimate the effects of major roads and public transit on the growth of major cities in the US between 1980 and 2000. We find that a 10% increase in a city’s stock of roads causes about a 2% increase in its population and employment and a small decrease in its share of poor households over this 20 year period. We also find that a 10% increase in a city’s stock of large buses causes about a 0.8% population increase and a small increase in the share of poor households over this period. To estimate these effects we rely on an instrumental variables estimation which uses a 1947 plan of the interstate highway system and an 1898 map of railroads as instruments for 1980 roads.

 

 

Assessing the effects of local taxation using microgeographic data (with  Henry Overman and Laurent Gobillon) (.pdf)

 

We study the impact of local taxation on the location and growth of firms. Our empirical methodology pairs establishments across jurisdictional boundaries to estimate the impact of taxation. Our approach improves on existing work as it corrects for unobserved establishment heterogeneity, for unobserved time-varying site specific effects, and for the endogeneity of local taxation. Applied to data for English manufacturing establishments we find that local taxation has a negative impact on employment growth, but no effect on entry.

 

 

Is the division of labour limited by the extent of the market? Evidence from French cities (with Hubert Jayet)   (.pdf)

 

This paper provides some evidence that the division of labour is limited by the extent of the (local) market. We first propose a theoretical model. Its main prediction is that scarce occupations are over-represented in large cities. Using census data for French cities, we then provide strong empirical support for this prediction.

 

 

California Dreamin’: The feeble case for cluster policies  (.pdf)

 

This study examines the case for cluster policy. This case is theoretically ambiguous and empirically very weak.

 

 

The Economics of Clusters: Evidence from France (with Philippe Martin, Thierry Mayer, and Florian Mayneris)  (.pdf)

Book forthcoming at Oxford University Press

 

 

 

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