Current Research

Current Research

Mobility and congestion in urban India
(with Prottoy A. Akbar, Victor Couture and Adam Storeygard)   Abstract  

We develop a methodology to estimate robust city-level vehicular mobility indices, and apply it to 154 Indian cities using 22 million counterfactual trips measured by a web mapping service. There is wide variation in mobility across cities. An exact decomposition shows this variation is driven more by differences in un-congested mobility than congestion. Under plausible assumptions, a one-standard-deviation improvement in uncongested speed creates much more mobility than optimal congestion pricing. Denser and more populated cities are slower, only in part because of congestion. Urban economic development is correlated with better (uncongested and overall) mobility despite worse congestion.
The production function for housing (with Laurent Gobillon and Pierre-Philippe Combes) Under revision.  Abstract  

We propose a new non-parametric approach to estimate the production function for housing. Our estimation treats output as a latent variable and relies on the first-order condition for profit maximisation with respect to non-land inputs by competitive house builders. For parcels of a given size, we compute housing by summing across the marginal products of non-land inputs. Differences in non-land inputs are caused by differences in land prices that reflect differences in the demand for housing across locations. We implement our methodology on newly-built single-family homes in France. We find that the production function for housing is reasonably well, though not perfectly, approximated by a Cobb-Douglas function and close to constant returns. After correcting for differences in user costs between land and non-land inputs and taking care of some estimation concerns, we estimate an elasticity of housing production with respect to non-land inputs of about 0.80.
Urban growth and its aggregate implications (with Diego Puga)   Abstract  

We develop an urban growth model where human capital concentration promotes entrepreneurship and raises city productivity. Land-use regulation balances commuting and housing costs against productivity gains to benefit local residents. Systematic determinants and productivity shocks drive city growth, generating realistic city-size distributions. Cities experience parallel growth in expectation, while subject to ups and downs around this common trend. Growth of exist- ing cities and net city entry accommodate aggregate population growth. Matching key empirical moments at the city and economy-wide levels, we explore the contribution of cities to aggregate growth and income levels and the economy-wide consequences of land use regulations.
Transportation infrastructure in the US (with Geetika Nagpal and Matt Turner).Chapter in revision for Economics of Infrastructure, edited by Ed Glaeser and Jim Poterba, NBER volume.
The economics of density (with Diego Puga)
Manuscript solicited by the Journal of Economic Perspectives.

Place-based policies for development
(with Anthony J. Venables)   Abstract  

Many development policies, such as placement of infrastructure or local economic development schemes, are “place-based.” Such policies are generally intended to stimulate private sector investment and economic growth in the treated place, and as such they are difficult to appraise and evaluate. This paper sets out a framework for analyzing the effects of such policies and assessing their social value. It then reviews the literature on place-based policies in the contexts of transport improvements, economic corridors, special economic zones, lagging regions, and urban policies.

The misallocation of land and other factors of production in India
(with Ejaz Ghani, Arti Grover Goswami, and William Kerr)   Abstract  

This paper quantifies the misallocation of manufacturing output and factors of production between establishments across Indian districts during 1989–2010. It first distills a number of stylized facts about misallocation in India, and demonstrates the validity of misallocation metrics by connecting them to regulatory changes in India that affected real property. With this background, the study next quantifies the implications and determinants of factor and output misallocation. Although more-produc- tive establishments in India tend to produce more output, factors of production are grossly misallocated. A better allocation of output and factors of production is associ- ated with greater output per worker. Misallocation of land plays a particularly important role in these challenges.
Measuring the cost of congestion in a highly congested city: Bogotá (with Prottoy Akbar)
Abstract and paper forthcoming.
The roadway of US metropolitan areas (with Erick Guerra)
The lifecycle of land: Evidence from the US, 2000-2010 (with Henry Overman, Diego Puga, Tanner Regan, and Matthew Turner)
Growth in cities revisited
The economic effects of high-speed trains (with Laurent Gobillon and Miren Lafourcade)