Justin Tyndall

Peer Reviewed ​Publications

The Effect of Front-end Vehicle Height on Pedestrian Death Risk
2024, Economics of Transportation, forthcoming.
Abstract ↓

Pedestrian deaths in the US have risen in recent years. Concurrently, US vehicles have increased in size, which may pose a safety risk for pedestrians. In particular, the increased height of vehicle front-ends may present a danger for pedestrians in a crash, as the point of vehicle contact is more likely to occur at the pedestrian's chest or head. I merge US crash data with a public data set on vehicle dimensions to test for the impact of vehicle height on the likelihood that a struck pedestrian dies. After controlling for crash characteristics, I estimate a 10 cm increase in the vehicle's front-end height is associated with a 22% increase in fatality risk. I estimate that a cap on front-end vehicle heights of 1.25 meters would reduce annual US pedestrian deaths by 509.

Homeowner Politics and Housing Supply
​     w. Limin Fang and Nathan Stewart

2023, Journal of Urban Economics, 138.
Abstract ↓

This paper examines whether homeowner opposition to nearby housing development affects local councillors’ votes on housing bills. Homeowners benefit financially from restricted housing supply through increased housing prices. City councillors, who approve housing development applications, cater to the needs of homeowners who are often long-term resident voters with a financial stake in neighbourhood amenity levels. Using data from Toronto, Canada from 2009 to 2020, we identify housing bills through a machine learning algorithm. We find that councillors who represent more homeowners oppose more housing bills. In particular, councillors are significantly more likely to oppose large housing developments if the project is within their own ward.

The Effect of Bus Rapid Transit on Local Home Prices
​     w. Justin Beaudoin
2023, Research in Transportation Economics, 102.
Abstract ↓

Bus Rapid Transit (BRT) systems have become increasingly common in US cities. BRT stations provide a local amenity by improving transportation options for local residents, but may also represent a local nuisance due to noise or displacement of other road users. We estimate whether BRT is priced into local real estate by studying a recently opened BRT project in Vancouver, Washington. We use a difference-in-difference method with both hedonic and repeat sales estimators to test for a price effect. We estimate a 5-7% price premium for homes located within a 20 minute walk of a BRT station. Overall, BRT generated new real estate value that exceeded the project's construction costs by a factor of six. We discuss how government could leverage future residential property value increases to fund construction of BRT projects.

The Impact of Recreational Marijuana Dispensaries on Crime: Evidence from a Lottery Experiment
​     w. Xiuming Dong
2023, Annals of Regional Science, forthcoming.
Abstract ↓

Many North American jurisdictions have legalized the operation of recreational marijuana dispensaries. A common concern is that dispensaries may contribute to local crime. Identifying the effect of dispensaries on crime is confounded by the spatial endogeneity of dispensary locations. Washington State allocated dispensary licenses through a lottery, providing a natural experiment to estimate the causal effect of dispensaries on neighborhood-level crime. Combining lottery data with detailed geocoded crime data, we estimate that the presence of a dispensary has no significant impact on local crime in the average neighborhood. We estimate a small rise in property crime in low-income neighborhoods specifically.

Highways and Pedestrian Deaths in US Neighborhoods
​     w. Cody Nehiba
2023, Regional Science and Urban Economics, forthcoming.
Abstract ↓

Over 100,000 pedestrians have been struck and killed by vehicles on US roadways in the first two decades of the 21st century, representing an alarming public health issue. We examine the US Interstate Highway System's legacy in contributing to local pedestrian deaths using historical Interstate Highway plans as an instrument for local Interstate construction. Operating an Interstate through a census tract increased pedestrian deaths significantly. Among 17,000 tracts bisected by Interstates, we estimate the average tract experienced 2.5 additional pedestrian deaths between 2001-2020 due to the presence of the Interstate. We find these deaths occur disproportionately in Black communities.

Sea Level Rise and Home Prices: Evidence from Long Island
2023, The Journal of Real Estate Finance and Economics, 67, 579-605.
Abstract ↓

Global sea level rise is a known consequence of climate change. As predictions of sea level rise have grown in magnitude and certainty, coastal real estate assets face an increasing climate risk. I use a complete data set of repeated home sales from Long Island in New York State to estimate the appreciation discount caused by the threat of sea level rise. The repeat sale methodology allows for time-invariant, unobserved property characteristics to be controlled for. Between 2000 and 2017, I find that residential properties that were exposed to future sea level rise experienced an annual price appreciation rate of roughly one percentage point below unexposed properties. I provide numerous robustness checks to confirm this result. I also find evidence of demand spillovers by estimating an appreciation premium for properties that are near the coast but are relatively safe from sea level rise.

Complementarity of Dockless Mircomobility and Rail Transit
2022, Journal of Transport Geography, 103..
Abstract ↓

Shared micromobility services have undergone rapid growth in cities throughout the world, including expansions in bike sharing and e-scooter sharing services. Shared micromobility provides a potential complement to public transit by accommodating first and last-mile trips. I analyze detailed data on shared, dockless bikes and e-scooters from Seattle, Washington. I find micromobility vehicles cluster near Seattle's rail transit stations. During the study period, Seattle expanded its rail system into a new section of the city. I use the system expansion as a natural experiment to provide evidence of complementarity between shared micromobility and public transit. Using a difference-in-difference strategy I find that, after a new light rail station opened, the flow of new micromobility vehicles increased significantly within a five minute walking radius of the station. I provide causal evidence that local rail transit increases the use of dockless micromobility vehicles.

Cycling Mode Choice Amongst US Commuters: The Role of Climate and Topography
2022, Urban Studies, 59(1).
Abstract ↓

Cycling to work is uncommon in most areas of the US, but relatively common in a particular set of metros and neighbourhoods. Explanations for this spatial heterogeneity often focus on differences in local geography, with some areas being allegedly more suitable for cycling. I estimate the role of topography and climate in determining the share of a metro's workers who cycle to work and the probability a particular worker chooses to cycle. I combine a US wide data set of commute flows with detailed elevation and climate data. I find that climate and topography play essentially no role in explaining cycling mode share across metros. Across workers, the hilliness of a commuter's route is found to be statistically irrelevant to cycling mode choice.

Pedestrian Deaths and Large Vehicles
2021, Economics of Transportation, 26.
Abstract ↓

Traffic fatalities in the US have been rising among pedestrians even as they fall among motorists. Contemporaneously, the US has undergone a significant shift in consumer preferences for motor vehicles, with larger Sport Utility Vehicles comprising an in- creased market share. Larger vehicles may pose a risk to pedestrians, increasing the severity of collisions. I use data covering all fatal vehicle collisions in the US and exploit heterogeneity in changing vehicle fleets across metros for identification. Between 2000 and 2019, I estimate that replacing the growth in Sport Utility Vehicles with cars would have averted 1,100 pedestrian deaths. I find no evidence that the shift towards larger vehicles improved aggregate motorist safety.

The Local Labour Market Effects of Light Rail Transit
2021, Journal of Urban Economics, 124.
Abstract ↓

Many US cities have made large investments in light rail transit in order to improve commuting networks. I analyse the labour market effects of light rail in four US metros. I propose a new instrumental variable to overcome endogeneity in transit station location, enabling causal identification of neighbourhood effects. Light rail stations are found to drastically improve employment outcomes in the surrounding neighbourhood. To incorporate endogenous sorting by workers, I estimate a structural neighbourhood choice model. Light rail systems tend to raise rents in accessible locations, displacing lower skilled workers to isolated neighbourhoods, which reduces aggregate metropolitan employment in equilibrium.

Getting High and Low Prices: Marijuana Dispensaries and Home Values
2021, Real Estate Economics, 49(4), 1093-1119.
Abstract ↓

Laws concerning marijuana have recently undergone liberalization in many North American markets. The changing legal environment has enabled the establishment of retail marijuana dispensaries. Local externalities generated by dispensaries may impact home values, particularly by influencing demand for the surrounding neighbourhood. Recent empirical evidence has found a positive effect of dispensaries on home values. I use unique data on 84 dispensaries and 62,000 repeat home transactions from Vancouver, Canada to estimate the effect of dispensaries on home prices. Historical Google Street View images are used to construct a longitudinal record of dispensary activity. I find no evidence that dispensaries increase local home values in Vancouver and some evidence of a negative price effect for homes located within 100 meters of a dispensary.

Free-floating Carsharing and Extemporaneous Public Transit Substitution
2019, Research in Transportation Economics, 74, 21-27.
Abstract ↓

The importance of substitution patterns between public transit and carsharing has been discussed in prior literature. This study provides empirical evidence of significant interaction between the two modes. On November 24, 2015 the public transit rail system in Vancouver, Canada experienced a significant service disruption due to an unforeseen mechanical failure. This study exploits this event as a natural experiment and investigates to what extent the city's largest carsharing service was utilized as a substitute. Extensive carsharing vehicle location data are used to examine how the carsharing network responded to the transit service disruption. Empirical results show a dramatic increase in the use of carsharing vehicles during the transit outage, particularly in areas close to affected transit stations. Through regression analysis, the quantity of vehicle trips accommodated by the carsharing system in response to the outage is estimated to be approximately 800. There is clear evidence of extemporaneous substitution between public transit and carsharing, suggesting the two modes act as parts of an integrated network.

Bus Quality Improvements and Local Commuter Mode Share
2018, Transportation Research Part A: Policy and Practice, 113, 173-183.
Abstract ↓

The choice to use bus transit over a rival mode of transportation is a consequence of many variables. The importance of bus service quality on mode share is often considered but rarely measured explicitly. This study presents a novel temporal data set of geolocated buses from New York City. The merger of locational vehicle data with public schedule data allows for the estimation of bus dependability across neighbourhoods. This study uses plausibly exogenous spatial variation in the introduction New York City’s Select Bus Service program to explore the relationship between the policy intervention, bus service quality and changes in commuter mode share. A propensity score matching procedure compares bus reliability and mode share in tracts that received Select Bus Service to a control group. A sizeable treatment effect is found. The policy intervention significantly increased service frequency and improved bus arrival reliability. Additionally, bus mode share amongst commuters in treatment neighbourhoods increased substantially. Select Bus Service was responsible for an increase in local bus mode share of 1.9 percentage points, with bus mode share in the median tract rising from 9.6% to 11.5%. Female commuters are found to be more responsive to the service improvements than males.

Where No Cars Go: Free-floating Carshare and Inequality of Access
2017, International Journal of Sustainable Transportation, 11(6), 433-442.
Abstract ↓

Carsharing programs have demonstrated a potential to significantly shift incentives with regard to private vehicle ownership. The advent of free-floating vehicle fleets has enabled providers to offer ubiquitous vehicle access in designated urban areas. The ability of users to choose where to drop off vehicles presents the possibility that the density of available vehicles in particular areas will be insufficient to supply a reasonable level of service to local residents. The current paper will use exclusive data on vehicle location from a free-floating carshare service that operates in ten U.S. cities. Analysis will relate the availability of vehicles to census tract demographics. Results show vehicles cluster in tracts that are disproportionately populated by residents who are educated, young, employed, and white. Carshare systems have received significant in-kind incentives from government to operate. The mobility benefits of free-floating carshare systems appear to accrue disproportionately to advantaged populations.

Waiting for the R Train: Public Transportation and Employment
2017, Urban Studies, 54(2), 520-537.
Abstract ↓

Expanding employment opportunities for citizens has become an increasingly central goal of public policy in the United States. Prior work has considered that the inability of households to spatially access jobs may be a driver of unemployment. The provision of public transportation provides a viable policy lever to increase the number of job opportunities available to households. Previous research has yielded mixed results regarding whether household location is an important factor in determining employment status. Several papers have identified mobility as a limiting factor for obtaining a job, particularly in regards to private vehicle ownership. The location of economically developed neighbourhoods and the citing of public transportation are conceivably codetermined, presenting an endogenous relationship. It is therefore unclear if public transportation access is actually contributing to neighbourhood job market outcomes. This paper will use the incidence of Hurricane Sandy striking New York City on 29 October 2012 and the resulting exogenous reduction in public transit access to particular neighbourhoods as a natural experiment to test for the effect of public transportation on employment outcomes. This study identifies a significant causal effect linking public transportation access to neighbourhood unemployment rates, particularly amongst subgroups dependent on public transit.

Working Papers

Urban Rail Transit and Endogenous Worker Choices
Abstract ↓

The provision of public transportation can improve the accessibility of work opportunities, particularly for low-income residents. However, predicting the labor market effects of new transit infrastructure is difficult because workers may endogenously adjust location, commute mode, and work decisions based on the existence of the infrastructure. I examine a large public transit rail project on the island of Oʻahu, Hawaiʻi. Using a matrix of census block level travel times, I propose and estimate a structural model of location and mode choice for workers on Oʻahu. I use estimated parameters to predict the effects of the rail project. I find the new rail system substantially increases the use of public transit and increases the employment rate, particularly among low-income workers. Accounting for endogenous household decisions through structural modeling is key to the findings. High-income workers have a strong preference for driving and a low preference for the neighborhoods in which rail was constructed, this allows low-income workers to capture a high share of transit's direct benefits.

Estimating Commuter Benefits of a New Transit System: Evidence from New York City's Ferry Service
Abstract ↓

This paper estimates the impact of a new transit system on worker outcomes, accounting for endogenous worker decisions. I examine the phased opening of New York City's commuter ferry system. I find evidence of a small but significant shift in commuting flows, towards routes with ferry service, driven by high-income workers. I then propose and estimate a novel structural neighborhood choice model that recovers workers' valuation of ferry service and the aggregate effects of the system on employment. Routes selected for ferry service matched the location preferences of high-income workers, allowing high-income workers to capture almost all direct benefits from the new system. Differing home and work location preferences across income groups largely determine who benefits from a new transit system.