Essays in macroeconomic theory and natural resources

This dissertation covers topics in the fields of macroeconomics and environmental economics. Using both theoretical and empirical methods, it focuses on the effects of population aging, climate change, and natural resource use on economic growth and the setting of optimal fiscal and climate policies. Specifically, the second chapter shows that optimal climate policies must be adjusted when there are other intertemporal distortions in the economy, for instance, capital income taxes. The third chapter derives a simple formula for the social costs of carbon and proposes a time-varying social discount factor that allows climate policies to reflect demographic trends. The fourth chapter explores the effects of energy innovation and policy on economic growth rates within the US. The last chapter analyzes optimal fiscal policies in an economy with endogenous retirement and demographic change.