Essays in Environmental and Health Economics

The dissertation examines the effectiveness of energy and transportation policies and their implications for the environment and public health.;Given the usual absence of data on vehicle flows, I use ambient concentrations of carbon monoxide (CO) as a proxy. CO is primarily emitted from mobile sources and is considered a good proxy for vehicle flows because its concentrations generally follow the spatial and temporal distributions of traffic. Based on this, the first essay conceptually defines the "fuel price elasticity of vehicular emissions," and then estimates it for a sample of US metropolitan areas using CO concentrations as an outcome measure. The estimated average elasticity across sample areas ranges from -0.20 to -0.34 depending on the specifications for the trend; the preferred specification yields an estimate of -0.29. It is equivalent to a 2.3% reduction of CO concentrations in response to a 10-cent increase in real gasoline prices. Further, I investigate whether the emissions sensitivity differs across regions, and find some evidence of heterogeneity in the elasticity estimates. Vehicular emissions tend to respond less sensitively in the sample areas with lower average CO concentrations, shorter commuting time, and less public transit usage. This suggests that local characteristics, such as alternative transportation modes, need to be considered when designing fuel price policies.;Programs to reduce traffic congestion and air pollution by restricting use of motor vehicles on working days have generally not met with success based on existing studies of such programs. The second essay provides the first study of Quito, Ecuador's four-year-old Pico y Placa driving restrictions program, and finds that it has reduced ambient concentrations of CO by 9-11% during peak traffic hours. For an extended daytime period that encompasses hours when population exposure to air pollution is likely to be highest, CO concentrations have been reduced by approximately 6%. Given the close relationship between CO concentrations and traffic, the results suggest similar reductions in vehicle flows.;A number of health studies discuss and find a significant association between air pollution and negative health outcomes. The driving restrictions program in Quito has decreased air pollution levels. The effect has diminished, but it continues to induce reductions in pollution levels well after its introduction in May 2010. Using hospital discharge data, the third essay extends the analysis of Quito's driving restrictions program to its effect on public health. The effects on the hospitalization rates of the populations most sensitive to air pollution are examined. Count data analysis that accounts for overdispersion in hospitalization reveals that some health benefits have accrued after the imposition of the driving restrictions; there has been a reduction in the elderly's cardiovascular hospitalization rate. The estimated effect is equivalent to a decrease in the total hospital admissions of the elderly by 1.3%.