Chapter 1 of this highly detailed book examines the flow of foreigners who receive their doctorate in the US by area of origin and destination, wealth of origin and destination area, and field of specialization. The backgrounds and characteristics of US citizens who go abroad for employment are compared with those of citizens remaining in the US. Chapter 2 reviews the history of PhD-producing schools and its effect on geographic distributions of population. The problem of a state-by-state versus a national point of view with respect to education and employment of high level personnel is described in Chapter 3. Chapter 4 seeks to explain the dynamics of migration by analysis of a large number of state characteristics related to migration. Chapter 5 explores follow-up data collected and maintained by the National Science Foundation for its National Register of Scientific and Technical Personnel. Geographic migration, employment, and principal work activities actually experienced are compared with expectations at the time of PhD graduation. Chapter 6 lists some unanswered questions regarding the mobility of high-level personnel. Figures and tables illustrate the discussion. (JS)