Local opinion leaders may play a key role in easing information frictions associated with technology adoption. This paper analyzes the influence of physician investigators who lead clinical trials for new cancer drugs. By comparing diffusion patterns across 21 new cancer drugs, we separate correlated regional demand for new technology from information spillovers. Patients in the lead investigator's region are initially 36% more likely to receive the new drug, but utilization converges within four years. We also find that superstar physician authors, measured by trial role or citation history, have broader influence than less prominent authors.

Social Security Disability Insurance (DI) awards rise in recessions, especially for workers over age 50. We use Medicare data to investigate how health, entry costs, and age-based DI eligibility rules shape this pattern. Entrants induced by recessions have lower medical spending and mortality than typical recipients. Entry responses to unemployment jump two- to fourfold at ages 50 and 55, when eligibility rules relax. Using these age-based discontinuities as instruments, we find no shift in marginal entrants' health across unemployment levels. These findings show that DI's age-based eligibility rules are a primary driver of cyclical entry, while health shocks are not.

We estimate how the mortality effects of temperature vary across U.S. climate regions to assess local and national damages from projected climate change. Using 22 years of Medicare data, we find that both cold and hot days increase mortality. However, hot days are less deadly in warm places while cold days are less deadly in cool places. Incorporating this heterogeneity into end-of-century climate change assessments reverses the conventional wisdom on climate damage incidence: cold places bear more, not less, of the mortality burden. Allowing places to adapt to their future climate substantially reduces the estimated mortality effects of climate change.

We study how air pollution impacts the U.S. labor market by analyzing the effects of drifting wildfire smoke. We link satellite-based smoke plume data with labor market outcomes to estimate that an additional day of smoke exposure reduces quarterly earnings by about 0.1%. Extensive margin responses, including employment reductions and labor force exits, explain 13% of the overall earnings losses. The implied welfare costs from lost earnings due to air pollution exposure is on par with standard valuations of the mortality burden. The findings highlight the importance of labor market channels in air pollution policy responses.