Recent and Forthcoming Research

If you have any recent working papers or forthcoming papers, please the authors, title and abstract to Felix Friedt (

May 12, 2020

  • Zhang, Y, A. Zhang and J. Wang (2020), “Exploring the roles of high-speed rail, air and coach services in the spread of COVID-19 in China” (April 10, 2020)  (available on SSRN:

Abstract:  To understand the roles of different transport modes in the spread of COVID-19 pandemic across Chinese cities, this paper looks at the factors influencing the number of imported cases from Wuhan and the spread speed and pattern of the pandemic. We find that frequencies of air flights and high-speed train (HST) services out of Wuhan are significantly associated with the number of COVID-19 cases in the destination cities. The presence of an airport or HST station at a city is significantly related to the speed of the pandemic spread, but its link with the total number of confirmed cases is weak. The farther the distance from Wuhan, the lower number of cases in a city and the slower the dissemination of the pandemic. The longitude and latitude coordinates do not have a significant relationship with the number of total cases but can increase the speed of the COVID-19 spread. Specifically, cities in the higher longitudinal region tended to record a COVID-19 case earlier than their counterparties in the west.  Cities in the north were more likely to report the first case later than those in the south. The pandemic may emerge in large cities earlier than in small cities as GDP is a factor positively associated with the spread speed.

  • Weber, B. S. (2019). Uber and urban crime. Transportation research part A: policy and practice, 130, 496-5061

This paper investigates the association of Uber, a substantial transportation innovation, with crime counts in urban areas that have accepted the program. I find the introduction of Uber to be associated with a large and significant reduction of personal crimes by 5% in treated cities (about 43 personal crimes a month, roughly 41 assaults), and discuss several mechanisms through which Uber may be enacting this change. The detailed data set allows us to identify that this crime reduction is equally significant on the weekends, when Uber is expected to deliver the most rides to and from bars. Furthermore, the significant personal crime reduction is almost entirely composed of assaults, which are known to typically be alcohol-related, while no significant reduction occurs in the plausibly irrelevant crimes against property, society, or other personal crimes. These estimates suggests that such ride-sharing programs may have positive effects toward crime reduction that otherwise may not inherently be taken into account by policy makers.

  • Heywood, J. S., & Weber, B. (2019). University-provided transit and crime in an urban neighborhood. The Annals of Regional Science, 62(3), 467-495.

     This paper uniquely examines the influence of a new university bus service on urban crime. It concentrates on the interaction between the new bus service and a long-standing safe ride program. The new bus service is associated with a decline in safe rides, and such substitution raises the well-known concern that a fixed transit route may concentrate victims and criminals increasing crime along the new bus routes. Despite this concern, a series of difference-in-difference estimates demonstrate that the bus service reduces crime in the entire university neighborhood and that this reduction is actually largest along the new bus routes.

March 15, 2020

  • Felix L. Friedt and  Jeffrey P. Cohen“Valuation of Noise Pollution and Abatement Policy: Evidence from the Minneapolis-Saint Paul International Airport.” Forthcoming at Land Economics. 02/12/2020.

Aircraft noise pollution has adverse physical and mental health effects that are capitalized in the affected home values. We contribute to the literature estimating these noise discounts by our novel identification strategy that analyzes the “treatment effect” of two local government subsidized soundproofing initiatives near the Minneapolis-Saint Paul International airport. Combining a repeat-sales sample with data on aircraft noise pollution (1990-2014), we find a causal noise discount of around $25,000 per sale of noise-affected, but abatement-ineligible, properties, whereas abatement-eligible homes experience a negligible effect post soundproofing indicating a return on abatement investments as a high as 40% in Minneapolis.

  • Felix L. Friedt and Wesley W. Wilson, “Trade, Transport Costs, and Trade Imbalances: An Empirical Examination of International Markets and Backhauls.”  Forthcoming at Canadian Journal of Economics

The U.S. trade de cit has been growing for over 25 years and has been accompanied by enlarging freight rate differentials. While traditional models of trade have ignored these gaps assuming symmetry across all bilateral trade costs, the specific linkages between trade imbalances and international transportation costs have remained unexplored. Given the current trade policies, the implications arising from the endogenous adjustment of bilateral transport costs to policy-induced changes in the U.S. trade de cit, for example, are of particular importance. To break new ground on this issue, we develop and estimate a model
of international trade and transportation that accounts for the e ects of persistent trade imbalances. The theoretical results are supported by our empirical analysis and indicate that bilateral transport costs adjust to a country’s trade imbalance. The implication is that a unilateral import policy, for example, will cause spillover eff ects into the bilaterally integrated export market. To illustrate, we use our empirical results to simulate the anticipated spillover eff ect from the Chinese ban on waste imports. We nd that China’s ban and the projected 1.5% rise in the U.S. trade de cit will not only lead to a 0.77% reduction of transport costs charged on U.S. exports to China, but also a 0.34% increase in transport costs on U.S. imports from China.

  • “Who (Else) Benefits from Electricity Deregulation? Coal prices, natural gas and price discrimination.” With Ian Lange. Forthcoming at Economic Inquiry.

The movement to deregulate major industries over the past 40 years has produced large efficiency gains. However, distributional effects have been more difficult to assess. In the electricity sector, deregulation has vastly increased information available to market participants through the formation of wholesale markets.  We test whether upstream suppliers, specifically railroads that transport coal from mines to power plants, use this information to capture economic rents that would otherwise accrue to electricity generators.  Using natural gas prices as a proxy for generators’ surplus, we find railroads charge higher markups when rents are larger.  This effect is larger for deregulated plants, highlighting an important distributional impact of deregulation.  This also means policies that change fuel prices, such as carbon pricing or increased pipeline building, can have substantially different effects on downstream consumers in regulated and deregulated markets.

  • “When Should Carpools in HOV Lanes be Encouraged?” With Daniel Kaffine. Economic Inquiry 57(1), pp. 667-684, January 2019.

Policies to encourage carpooling in high-occupancy vehicle (HOV) lanes have been adopted in the US to lower congestion and reduce air pollution.  We analytically model highway congestion and other vehicle-related externalities.  Encouraging carpooling decreases total costs when congestion relief in mainline lanes outweighs increased HOV lane congestion.  Importantly, entry of new drivers via induced demand can negate the benefits of increased carpooling.  Using 10 years of traffic data from Los Angeles we estimate time and route-specific marginal external costs.  Because costs vary substantially across routes, hours and days, current policies to promote carpooling will often increase social costs.