The three chapters of this dissertation explore topics in health economics, namely how early-childhood health circumstances affect long-run health and economic outcomes, as well as how insurance reimbursement impacts the nature of physician practices. The first chapter assesses the impact of in utero and early-childhood exposure to wildfire smoke on longevity. To identify areas that were exposed to wildfire pollution, we leverage mid-20th century (1930-1969) California wildfires and smoke dispersion modeling. We then combine these wildfire pollution data with comprehensive, restricted-use administrative data. These linked data allow us to measure childhood wildfire smoke exposure for four decades of birth cohorts and to observe a rich set of later-life outcomes. Using these data, we exploit plausibly exogenous variation in smoke exposure—which is a function of fire timing and size as well as wind direction and speed—to identify long-run effects. We find that moving from the 25th to 75th percentile of early-life wildfire smoke exposure results in 1.7 additional deaths before age 55 per 1,000 individuals, conditional on surviving past early childhood. Aggregating these effects across ages 30 to 80 translates to 46 life years lost per 1,000 persons. The second chapter considers the impact of in utero and early-childhood exposure to wildfire smoke on longevity as well as economic achievement, human capital accumulation, and disability in mid-to-late adulthood. To identify areas that were exposed to wildfire pollution, we leverage mid-20th century (1930-1969) California wildfires and smoke dispersion modeling. We then combine these wildfire pollution data with comprehensive, restricted-use administrative data from the Social Security Administration and Census Bureau. These linked data allow us to measure childhood wildfire smoke exposure for four decades of birth cohorts and to observe a rich set of later-life outcomes. Using these data, we exploit plausibly exogenous variation in smoke exposure—which is a function of fire timing and size as well as wind direction and speed—to identify long-run effects. We find that moving from the 25th to 75th percentile of early-life wildfire smoke exposure results in 1.7 additional deaths before age 55 per 1,000 individuals, conditional on surviving past early childhood. Aggregating these effects across ages 30 to 80 translates to 46 life years lost per 1,000 persons. We further find that smoke exposure results in unfavorable changes to a wide range of later-life outcomes across economic achievement, educational attainment, and disability measures. From these results, we estimate that each child born in California during our sample period sustained, on average, approximately $22,000 of discounted damages in lost life expectancy and lost earnings due to wildfire smoke. These findings suggest that warming temperatures, which exacerbate the duration and intensity of wildfire seasons, are already meaningfully affecting the life cycles of exposed children through increased smoke exposure. The third chapter exploits spatial discontinuities in Medicare payment rates to estimate the effect of reimbursements on primary care physicians’ choice of organizational structure. I find that a 1 percent increase in Medicare reimbursement leads to a 1.7 to 2.2 percentage point increase in primary care doctors who practice with a small group (defined as 25 providers or fewer). This effect is driven by changes in the tails of the practice size distribution: a 1.8 percentage point increase in physicians who are affiliated with the smallest (1- or 2-provider) practice groups with a corresponding decrease in physicians joining very large practices (≥ 150 providers). I do not, however, detect any evidence of physician sorting or bunching around the boundary in response to differential payment, supporting the underlying assumptions of my regression discontinuity design. Accordingly, my findings suggest that Medicare pricing may be a factor in the trend of consolidation in the physician and clinical services market.