SELECTED FACTORS AREALLY ASSOCIATED WITH POPULATION GROWTH DUE TO NET MIGRATION

Abstract

T N the scientific study of population, the I geographer attempts to arrive at valid generalizations, or statements of regularities, about a set of facts concerning the spatial distribution of population phenomena. In order to do so, he formulates hypotheses about areal associations or relationships which may exist between the population phenomenon under investigation and other phenomena. These hypotheses are based upon a set of observations, or facts. Sets of facts collected by governmental or other agencies are available; in the United States, for example, births and deaths are recorded, and many types of census are taken. Such data constitute the raw material which may be used to test hypotheses. It is obvious that since the resulting generalizations have been derived from the set of observations in the aggregate, they are in turn applicable to the entire set rather than to any particular observation or area. In other words, they account for the phenomenon as a whole, or on the average, rather than accounting for the circumstances in any one area. A scientific explanation consists essentially of such a statement of regularity about a set of facts. Study of the spatial aspects of migration is an important component of population geography. Geographers, as well as other social scientists, have used many different approaches in attempting to explain the observed movement of people. The use of migration probabilities has been pioneered by Swedish geographers, notably Hagerstrand1 and Kulldorff.2 The gravitational concept of human interaction has been employed by