Geographical migration patterns are, therefore, determined on the one hand by the location decisions of employing organization and the spatial division of labor they favor, and on the other by a group of eligible people with degrees of skill and experience already acquired. These are elements in a system the energy for which is provided by the need for employers to fill vacancies with the right sort of skills, and by the desire of employees for careers which present possibilities for promotion, job satisfaction and general improvement in lifestyle.