This is an award under the Grants for Improving Doctoral Dissertation Research Program. This study will examine the pathways to promotion within a single, large multi-level firm with data from job histories of employees hired between 1975 and 1985. It seeks to answer the question of why individuals who begin with what look like the same career chances often end up in different positions. This question is both of practical significance and is rooted in the theoretical literature on organizations. Analysis of career data will test statistical models of multiple career trajectories as these apply within firms. %%% This research contributes to sociological understanding of career mobility and the barriers to equality of advancement that may develop within firms. In addition to the scientific gains to be achieved by the research, this award will materially assist a highly promising student in completing research for the Ph.D. dissertation. Thus it contributes to the future scientific manpower of the nation and the thorough training of the next generation of social scientists.