This work uses ethnography, primary, and secondary sources to describe the changing role of women in fertility decision-making. It relates their choices to the internal economic structure of the municipio, and to the overall economic climate in Mexico, as constrained by that nation's place in the world-economy. It considers the impact of modernization on the municipio and analyzes the historical antecedents of present-day adaptations. Finally, it contributes to the general theory of fertility change through the analysis of data concerning these areas.

The last decade has seen a burgeoning of new work on population growth and decline. The widely cited notion of a "demographic transition", which correlates population change with industrialization, has not explained demographic trends in non-western countries. Early assumptions that improved survivorship of children would lead fertility to replacement levels have not proved accurate. Further, much of this work proceeds on the assumption that couples make joint decisions to regulate fertility. They neglect to consider how the woman, as a critical participant in the act of reproduction, influences such decisions.

For the women of Baviacora, Sonora, the interaction of modernization and economic crisis leads to changing fertility decisions. In the absence of wage labor or favorable market conditions they cannot increase their contribution to family income by postponing childbearing. They are faced with the day to day task of delegating dwindling household assets to escalating family needs. As the economic, physical and emotional costs of parenting rise rapidly, the only rational strategy for them is to quickly limit family size through fertility regulation. As their roles within the household take on more responsibility, their reproductive strategies become more autonomous. In this instance, women, not couples play the critical role in fertility decisions.

This study is an ethnography of women in a rapidly modernizing, rural municipio in northwest Mexico. It focuses on the individual decision-making processes which lie behind women's reproductive strategies, and how these are motivated by a two-way relationship between economic and biosocial factors. Set against the backdrop of Mexico's economic problems, it examines the ways in which the interaction of modernization and economic crisis lead to a restructuring of the allocation of time, energy, and resources for the women of Baviacora, Sonora.