NBER Working Papers by Matthew Turner

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.

Using extensive data on 1970 and 1987 urban characteristics, the paper analyzes changes in employment in specific manufacturing industries in cities between 1970 and 1987. Two sets of questions are the focus. First, what present or past characteristics of a city's economic environment are critical in determining current employment levels in different industries? How much persistence in employment patterns is there over time and what is the source of that persistence? The second set of questions explores what inferences can be made from the data and results concerning the nature of externalities in urban markets, involving diversity of suppliers to firms, information spillovers concerning current market conditions and information spillovers involving the spread of technology. While the lite...