[영문]AbstractPersonnel economics drills deeply into the firm to study human resource management practices like compensation, hiring practices, training, and teamwork. Why should pay vary across workers within firmsand how compressed should pay be within firms? Should firms pay workers for their performance on the job or for their skills or hours of work? How are pay and promotions structured across jobs to induce optimal effort from employees? Why do firms use teams and how are teams used most effectively? How should all these human resource management practices, from incentive pay to teamwork, be combined within firms? Personnel economists offer new tools to analyze these questionsand new answers as well.