In response to a request from the Manpower Administration of the U. S. Department of Labor, the book, authored by manpower researchers, develops a conceptual framework within which a labor market information system can be understood and implemented. Part 1 deals with a rationale and conceptual framework for governmental action designed to improve the flow of labor market information. Background information is presented concerning recent labor market transformations, assessment of actual job market transactions, manpower/employment flow subsystems, and basic characteristics of information and information systems. In part 2, five separate studies are presented of important subsystems of the encountered labor market information system: job markets; role of career guidance in educational institutions; use of labor market information by institutions of higher education, by urban employers, and by Federal policy-makers. The concluding section, part 3, summarizes conclusions and recommendations for the development of an effective labor market information system. The authors recommend simultaneous action on both the local and national levels of labor market information. Efforts to strengthen local labor market information collection/dissemination through a cooperative undertaking among governmental/private/nonprofit sectors are encouraged. Primary stress is on improving quality of present data and minimizing the initial collection of more data. (EA)