My dissertation consists of two essays. The essays analyze the equilibrium impact on asset risk premia of variation in the level of uncertainty and the risk of sizeable non-Gaussian (jump) shocks to important macroeconomic variables. The essays highlight the importance of uncertainty channels for understanding and quantitatively capturing the large and volatile risk premium embedded in equity index options, and the connection between variation in this option premium and expected equity returns. Uncertainty plays a key role in economics, finance, and decision sciences. Financial markets, in particular derivative markets, provide fertile ground for understanding how perceptions of economic uncertainty and cashflow risk manifest themselves in ...