Variation in U.S. Fertility: Low and Not so Low, but Not Lowest-Low

Abstract

In a discussion of low fertility and population aging, the United States stands out with a level of fertility hovering around the replacement level (substantially higher than that of most economically advanced countries) and a corresponding, modest pace of aging. As a result, government policy is not directed toward increasing or decreasing overall levels of fertility (United Nations 2011). Thus to contribute to a discussion of below-replacement fertility, the most relevant questions are: What accounts for the relatively robust U.S. fertility rate? And how does the U.S. experi- ence contribute to our understanding of the determinants of low and very low fertil- ity in other contexts? We address these questions by describing fertility levels and variation in the United States. For some groups, fertility is quite low, well below replacement. Other groups have fertility well above the replacement level. In order to understand this variation, we begin by introducing two compatible theoretical frameworks. The first posits a set of intermediate variables: the level of desired/intended fertility and fac- tors that constrain (e.g., sub- or infecundity) or augment (e.g., unwanted fertility) fertility relative to these intentions. These “intermediate” variables (that character- ize a “fertility regime”) are anchored in culture and social structure, and we also offer a conceptualization of these more distal causes. Both frameworks aid discus- sions of low fertility in the United States and, I argue, are useful for thinking about low fertility and policy options in all contexts.