In this dissertation, I investigate how policy interventions and structural economic changes shape population health, using causal inference methods and general equilibrium modeling. Chapter 1 examines the impacts of soda taxes experienced during early adolescence on health in adulthood, leveraging variation in the timing and magnitude of state-level soda taxes. I find that an increase in the soda tax rate during early adolescence is associated with a 1.1 percent decline in mortality from age 20 onward. The effect is especially pronounced for causes of death closely linked to obesity and excessive sugar intake. Further analyses indicate that higher soda tax exposure during adolescence is also associated with a 0.5 percent reduction in adult obesity rates.

Chapter 2 studies the impact of industrial robot adoption on workers' health. Results indicate that while industrial robots are associated with a decrease in nonfatal injuries, there is an increase in fatal injuries. Furthermore, the disparity of health risks across age groups has widened due to automation. The overall hospitalizations have declined in commuting zones with higher automation exposure. Yet, middle-aged workers experience increased hospitalizations, particularly due to despair-related conditions.

Lastly, Chapter 3 examines the distributional effects of pollution taxes within a general equilibrium framework, with particular attention to the health channel. Using wildfire smoke as an instrumental variable, I find that PM2.5 pollution has disproportionately negative impacts on labor force participation and employment among individuals with lower educational attainment. I then develop an analytical general equilibrium model with a closed form solution and show how a pollution tax, by improving population health, could mitigate its regressive effects through the health channel.