Fertility in urban areas of Mexico: Implications for the theory of the demographic transition

Abstract

Recent investigations indicate that fertility is not universally associated with urbanization and economic development in the manner predicted by the theory of the demographic transition. It is possible, however, that these investigations only partially test the theory, for the degree of industrialization in urbanareas is rarely taken into account. Two hypotheses are tested based upon Mexican census and vital registration data for 1940-60: (a) urban fertility is inversely related to the proportion of the urban population employed in the secondary sector of the economy and (b) changes in urban fertility are inversely related to changes in the proportion of the urban population employed in the secondary sector of the economy.At each census date from 1940 to 1960, the association between urban fertility (age-standardized child-woman ratio adjusted for infant mortality) and the percent in the secondary sector is low and positive. In 1960, however, the association is negative (suggesting a possible change in the direction of the association), but city growth rates and the proportion of females married are more closely related to fertility than percent in the secondary sector. Hypothesis a, then, receives little support from the data.Much the same is true of hypothesis b. The association between changes in urban fertility and changes in the percent in the secondary sector is positive. Moreover, city growth rates and changes in the proportion literate explain more of the variation in fertility change than does the percent in the secondary sector.In addition, over-all fertility has risen since 1940, and this rise is pronounced in large urban areas. It is suggested that among certain segments of Mexican society, the response to economic development has been an increase rather than a reduction in fertility. It is further suggested that if city growth is indicative of rural-urban migration, the presence of large numbers of rural migrants in urbanareas may help to explain the decreasing size of the urban-rural fertility differential in Mexico.If this interpretation is correct, the theory of the demographic transition is in need of further modification, specification, and verification.