Migration, Natural Increase and City Growth: The Case of Rio De Janiero

The processes associated with the demographic transition from high to low vital rates developing countries are progressively being understood as divergent from those prevailing during the chronologically earlier transitions occurring in the developed Western nations. The purpose of the present paper is to examine the nature of those demographic relationships which culminate in the unprecedented city growth of developing areas. In this particular domain the dearth of reliable information has led to diametrically-conflicting positions concerning the relative weights of the various components of urbanization (an increase in the proportion of urban population) and of city growth (an increase in the number of persons classified as urban) (Weller et al 1971). Moreover although several studies have concentrated on apportioning the relative contribution of natural increase and migration few have paid systematic attention to the factor of migrant natural increase. Such an oversight can assume considerable proportions since depending upon the dimensions of prior migratory moves migrant natural increase could conceivably play a commanding role even to the point of competing with either native natural increase or net migration. In an effort to illustrate the manner in which components of urban growth can concretely interact in an urban developing area the growth processes operating in Rio de Janeiro during the period 1920-1970 are presented here. The data which have been collected on migration-related topics there are in many ways exceptional and hence provide us with an opportunity of clarifying the interconnected etiology of city growth whether or not the substantive findings are strictly applicable to other developing areas. (excerpt)