The Spatial Diffusion of Fertility in Brazil: How Large Is the Effect?

Joseph E. Potter, University of Texas at Austin
Carl P. Schmertmann, Florida State University
Suzana M. Cavenaghi, Universidade Estadual de Campinas

In this paper we use a data set consisting of more than 100 million randomly-selected individual records from Brazilian censuses of 1960, 1970, 1980, 1991 and 2000 to address questions of spatial diffusion. We have aggregated individual-level records into approximately 500 spatial units (called microregions) that can be identified from geographical codes in all four censuses, and we have constructed fertility and development indices for each of the microregions in each census year from 1960 to 1991. We consider spatial interdependence postulating that, in addition to these covariates, fertility in region i is also related to the level of fertility, at the same time, in “neighboring” or other influential regions. First-differencing this model enables one to “explain” microregional fertility decline as a result of both local development, and of fertility change in the neighboring or influential regions.