Applied Econometrics

Key Findings

• The air quality index declines by approximately 1–2% in the year of Uber's entry into a city.
• The probability of unhealthy air quality episodes falls by 8–18% following Uber's introduction.
• Improvements result from substituting trips in older, less fuel-efficient vehicles with Uber rides in newer, cleaner cars.

Key Findings

• Agricultural workers aged 15–24 are over 10 times more likely to die from heat than peers in professional or managerial jobs.
• People under 35 account for 75% of heat-related deaths — overturning the assumption that elderly populations are most vulnerable.
• Occupation is a critical and previously underappreciated driver of climate vulnerability in developing countries.

Key Findings

• German LEZs reduce PM10 and NO2, but produce unintended increases in ozone and pollution spillovers into adjacent areas.
• Despite health benefits, LEZs cause transitory yet long-lasting reductions in residents' life satisfaction.
• The subjective well-being costs of restricted mobility appear to outweigh the perceived gains from improved health.

Key Findings

• Higher air pollution exposure leads to significantly more convictions by Indian judges across 10 million penal cases.
• Reducing average pollution by one standard deviation could lead to up to 145,000 fewer convictions among active cases.
• The mechanism operates through pollutants altering brain chemistry — causing fatigue, unstable risk preferences, and greater propensity to punish.

Key Findings

• Air pollution and crime follow an inverted U-shape: pollution first increases criminality, then decreases it at very high levels.
• Crime peaks at NowCast AQI values of ~150 and 116 in Mexico City; beyond these thresholds, avoidance behavior dominates.
• Analysis uses 2.9 million hourly observations — prior linear models may have mischaracterized the pollution-crime relationship.

Key Findings

• A 10 μg/m³ increase in PM2.5 lengthens court hearings by 6.8%; a 10 ppb increase in NO2 adds 5.1%.
• Reducing PM2.5 by 10 μg/m³ would save ~81,712 hearing minutes — equivalent to 56 days of court time.
• First evidence that air pollution impairs high-skill cognitive work, not just physical labor productivity.

Key Findings

• The 2013 floods affected 10% of all automatic traffic counters and 23% of all main roads in Germany.
• First study to quantify climate-related freight traffic variations across an entire national road network.
• Time-series outlier detection endogenously identifies affected counters and estimates the magnitude and duration of disruptions.

Key Findings

• Cold temperatures reduce ED visits by up to 8.9% on the same day and cumulatively by 16.3% over 30 days; warm temperatures increase visits by up to 3.6%.
• Unlike mortality, which shows a U-shaped response, ED visits respond approximately linearly to temperature — with limited harvesting for heat.
• Children and teenagers are more sensitive to heat; older populations are more vulnerable to cold. Climate projections indicate ED usage will rise, adding an estimated $86 million in annual medical costs by midcentury.

Key Findings

• A 2019 wage and fiscal reform in Mexican border municipalities significantly reduced temperature-related mortality in treated areas.
• Income gains increased adaptive capacity through higher electricity expenditures and the purchase of electric heaters.
• Results provide causal evidence that redistribution policies funded by carbon taxes can simultaneously address climate vulnerability and socioeconomic inequality.

Key Findings

• Countries experience material imbalances — disparities between production material needs and consumption waste — that drive international waste trade flows.
• Gravity model estimates show an elasticity of 0.8 between country-pair material imbalances and waste exports, confirming their role as a key determinant.
• Poorly designed recycling policies may encourage waste exports to developing countries rather than enhance domestic recycling, raising environmental and ethical concerns.

Key Findings

• A marginal increase in PM2.5 leads to a 2.3% rise in emergency department visit rates, using boundary layer height as a quasi-random instrument.
• Effects vary significantly by age group and exposure levels, with most increases driven by respiratory conditions.
• First nationwide assessment of air pollution-attributable ED demand in a developing country, covering the universe of public hospital triage visits in Mexico.

Key Findings

• While pollution fell within the restricted area, it increased in neighboring zones — leading to worse city-wide air quality overall.
• Aggregate effects suggest an increase in annual all-cause mortality of more than 900 additional deaths (3.7%).
• The policy exacerbated disparities in pollution exposure between high- and low-income neighborhoods.

Key Findings

• Indigenous municipalities face a persistent PM2.5 exposure gap of more than 1 μg/m³ compared to non-Indigenous areas.
• Cooking fuel differences explain up to 14% of the gap; atmospheric and orographic conditions account for up to 40%, linked to historical displacement into rugged terrain.
• Equalizing biofuel cooking shares could prevent ~120 premature deaths annually, with benefits of up to $26 million USD.

Key Findings

• Remittances to Mexico increase when temperatures are abnormally high or low in Mexico, reflecting greater need in origin communities.
• Remittances decrease when US temperatures are extreme, as heat and cold negatively affect migrant labor outcomes in destination communities.
• Uses transnational data on undocumented migrant networks to trace the climate-remittance channel across borders.

Key Findings

• Municipalities receiving FONDEN support experience lower cumulative inflation during the first 4–5 months post-disaster, as timely aid mitigates supply constraints.
• From 8 to 11 months after a disaster, inflation rises in treated areas, reflecting inflationary pressures from accelerated infrastructure investment.
• Uses a fuzzy regression discontinuity design exploiting exogenous rainfall thresholds for FONDEN eligibility.

Key Findings

• Each additional burn within 25 km raises monthly PM2.5 by 0.022 μg/m³, increases mortality by 0.057%, and reduces daily labor supply by 0.066 minutes per worker.
• A 10% reduction in agricultural burns could yield over $16 million USD in annual social benefits.
• 55% of benefits relate to lower mortality, 44% to reduced labor supply losses, and 1% to fewer ED admissions.

Key Findings

• Air purifiers reduce indoor PM2.5 concentrations by 32% and decrease student absenteeism by 12.5% in a cluster RCT across 95 primary school classes.
• Effects are larger among students with higher pre-treatment absenteeism; treated students report fewer respiratory symptoms and greater air quality awareness.
• Impact is greater when outdoor pollution is relatively low and diminishes as outdoor pollution intensifies, consistent with nonlinear marginal effects of air quality on health.