Since 1970 a number of occupation have shifted in gender composition, in some cases going from an almost all male to an almost all female workforce. A dual queuing process effectively models labor market dynamics. “Job queues and labor queues govern labor market outcomes: employers hire workers from as high in the labor queue as possible, and workers accept the best jobs available to them. As a result the best jobs go to the most preferred workers, and less attractive jobs go to workers in the labor queue; bottom-ranked workers may go jobless, the worst jobs may be left unfilled.