What keeps people in jobs or occupations is the central theme of four studies that interpret workers' attitudes toward job-changing in the light of their work experience as well as their expectations for the future. Gladys Palmer, in collaboration with Herbert S. Parnes of Ohio State University and Richard C. Wilcock of the University of Illinois, has experimented in the key study with analyses designed to measure the strength of a person's attachment to his or her occupation or employer. Attitude questions are given a time dimension by checking them against the job histories of individual workers and by including evaluations of crucial job decisions in the past. The effect of private pension plans upon the inclination to change jobs is examined by Parnes, with surprising results. A third study, by Carol P. Brainerd, considers the impact of the search for economic security on a highly skilled group by tracing changes over thirty years in the way toolmakers move between jobs and in the methods of training them. Mary W. Herman uses both America and European materials to analyze the connection between the ideas of social class, work attitude, aspirations for moving up the social scale, and the amount that actually occurs between different levels of skill. The volume emphasizes the work experience and attitudes of male production workers in the stable period of their working lives, when family responsibilities are usually heavy. At the same points, however, it also covers women workers and the full range of age groups in the adult population. In the concluding chapter, Palmer brings the findings together, examines their implications for understanding the complex factors that determine individual movements in the labor market, and assesses the various attitude measures developed as predictors of attachment or mobility. Materials, sources, and technical aspects of the analysis are discussed in four appendices. These studies have both practical appeal and research interest. Personnel workers, guidance counselors, employment specialists, and others involved in the everyday workings of the labor market will appreciate the insights into worker attitudes and behavior, while the analysis of institutional force and of motivations and trends in mobility will interest labor economists and sociologists, as well as technicians in the field of attitude research. Founded in 1921 as a separate Wharton department, the Industrial Research Unit has a long record of publication and research in the labor market, productivity, union relations, and business report fields. Major Industrial Research Unit studies as published as research projects are completed. This volume is Study no. 40.