This thesis is comprised of three chapters which discuss topics related to labor market dynamics from a macroeconomic perspective. Although each chapter is self-standing in terms of research question and methodology, they are united by a common interest for the macroeconomic implications of worker heterogeneity. The chapters vary with respect to the time horizon over which they study aggregate dynamics, covering business cycle frequency, the economy's long run steady state, and households' life cycle. Furthermore, they develop the concept of heterogeneity across different dimensions: stages of the life cycle, households' income and wealth, observed worker characteristics, and worker-firm productivity levels. The overall purpose of this thesis is therefore to contribute to the study of labor markets and labor policies through a multi-faceted approach.