The book collects articles published by Daniel Hamermesh between 1969 and 2013 dealing with the general topic of the demand for labor. The first section presents empirical studies of basic issues in labor demand, including the extent to which different types of labor are substitutes, how firms' and workers' investments affect labor turnover, and how costs of adjusting employment affect the dynamics of employment and patterns of labor turnover. The second section examines the impacts of various labor-market policies, including minimum wages, penalty pay for using overtime hours or hours worked on weekends or nights, severance pay for displaced workers, and payroll taxes to finance unemployment insurance benefits. The final section deals with general questions of discrimination by employers along various dimensions, including looks, gender and ethnicity, in all cases focusing on the process of discrimination and the behavior that results. Throughout the focus is on the development of theoretically-based hypotheses and testing them using the most appropriate data, often data collected uniquely for the particular project.