In 2019, Mongolia banned burning raw coal in the country's capital, Ulaanbaatar, to curb severe air pollution. This paper evaluates the policy and finds its effectiveness was undermined by a critical implementation failure. Using a difference-in-differences framework, we show the ban reduced particulate matter (PM10) by one-third of a standard deviation, but simultaneously increased sulfur dioxide (SO2) by three-quarters of a standard deviation. This perverse outcome was driven by a state-led shift to subsidized briquettes, revealing a failure of regulatory oversight. Consequently, we find no detectable improvement in child mortality rates, as the benefits from lower particulate pollution were likely nullified by the harm from increased SO2. The Ulaanbaatar case demonstrates that the success of environmental policy is contingent on the state's capacity for implementation and regulation, offering a critical lesson for clean air transitions globally.This study examines the impact of Premier League football matches on bike-sharing demand and cyclist safety near stadiums in London. Using a difference-in-differences framework with high-frequency data from the Santander Cycle Hire (SCH) system, I find that bike-sharing demand increases by 19% at stations 0.5–1.0 km from stadiums on game days, with smaller increases extending out to 2.0 km. Simultaneously, the probability that a cyclist-involved crash is classified as “serious,” typically requiring hospitalization, decreases by 18.4% within 1.5 km of stadiums on game days. I find no change in the overall number of crashes occurring near stadiums on game days. These findings are consistent with the “safety in numbers” effect, where increased cyclist visibility encourages safer driving behavior. The crash results are robust to placebo tests and alternative distance bands, with back-of-the-envelope calculations suggesting societal cost savings of £2.18 million over the sample period due to reduced crash severity. These findings highlight a positive externality of mega-events: while often criticized for congestion and disruption, game days can improve safety for vulnerable road users, offering actionable insights for policymakers and urban planners.I exploit the timing of public transit strikes in London to demonstrate that strikes have public health costs in the context of cyclist safety. Using a novel dataset that records the geo-location of all known cyclist-involved crashes in London between 2005-2018, I show the first day of a public transit strike causes a 18.67% increase in the number of cyclist-involved crashes in boroughs where the city has implemented bike- sharing stations. This increase in crashes primarily operates through the mechanism of increased cycling demand on strike days, as public transit strikes in London cause temporary substitution to the city’s bike-sharing system when transit by metro rail is unavailable. In future work, I plan to show how strikes affect the severity of crashes and how crashes evolve over time following a transit strike. London Traffic Congestion and Premier League Football Matches
This article analyzes the impact of Premier League football matches on local traffic conditions in London. Using high-frequency traffic loop detector data from 2015 and 2016, we examine changes in road speeds before, during, and after matches. Reduced form regressions show that average traffic speeds decrease by 4% on match days. Event-time analysis reveals that the largest congestion effects occur following matches, with speeds declining by 7.7% during the three hours after a match. Effects are strongest within 1 mile of stadiums and are concentrated on single-lane roads. Placebo tests 24 hours before and after matches show no significant impacts, suggesting that the observed congestion is event-driven. These results highlight the localized but substantial externalities that major sporting events impose on urban transportation networks, and suggest that policymakers should account for traffic impacts when evaluating the broader costs of professional sports facilities.Job Market Outcomes for Undergraduate Economics Majors
In this paper we set out to update the literature on labor market outcomes of undergraduate economics majors in the United States. Using 2014-2022 American Community Survey data on nearly four million individuals aged between 25 and 65 across all 50 states, we estimate the marginal effects of having three separate baccalaureate economics degrees—general, agricultural, and business—on wages and weeks worked per year. We find a positive, non-negligible, and statistically significant effect of having an economics degree on earnings after controlling for a large number of socio-economic individual- and state-level characteristics. The evidence is most robust for general (non-business and non-agricultural) economics majors. Alternatively, we find little evidence that having an economics major strongly affects quantity of labor supplied measures by weeks worked.The Impact of Bike-share Integration on Public Transit Demand
Research question and data identified.We replicate and extend a seminal field study to differentiate inefficiency of publicly-provided services from government corruption. Envelopes were sent to fictitious businesses at nonexistent addresses across 159 countries. Whether the letter was returned is the outcome variable of interest. By randomly treating one-half of the envelopes by including money in them, we induce public sector theft. We first establish a causal average treatment effect. Envelopes with money are 4.5 percentage points less likely to be returned. We then consider four important dimensions argued to be related to government service efficiency. we show that public sector management quality and public sector employee's beliefs about willingness to serve citizens and follow the rules correlate with our measurement of corruption, but technology, other attitudes, and compensation do not.