This lecture will be based on the recent Hoffman and Stanton Handbook of Labor Economics chapter on Personnel Economics.  In the chapter, we discuss foundational models and new research on incentives and compensation; hiring practices; the influence of managers and peers; and time use, technology, and training. Two main themes emerge. First, we illustrate the interplay between these topics and productivity differences between people and work units. We discuss evidence showing substantial and persistent productivity variation among workers in the same roles, and we examine the extent to which personnel economics research can explain this variation. Second, as many personnel studies use data from individual firms, we discuss external validity and provide concrete guidance on improving discussions of generalizability from specific contexts.