This document reviews (1) recent trends in labor force participation and employment among young men, paying specific attention to high school dropouts and minorities because their participation and employment rates have particularly declined; (2) several potential causes for the trends (including a decline in the demand for the labor of these young men and the resulting fall in the wages they are likely to receive) and the empirical evidence for believing them to be causes; (3) evidence on recent trends in participation and employment for different groups of young people; (4) the standard economic model of participation that generates potential causes of these developments; and (5) the empirical literature on demand-side and supply-side causes of participation changes, as well as additional evidence on employment changes for minorities. A final section provides policy implications, suggesting that it may be appropriate to implement policies that discourage dropping out of high school and that raise the demand for labor among the less educated by either enhancing their skills or by lowering their costs to employers. (The document includes 4 tables and 80 references.) (CML)