Early Fertility Decline in the United States: Tests of Alternative Hypotheses using New IPUMS Complete-Count Census Microdata and Enhanced County-Level Data.

The U. S. fertility transition in the nineteenth century is unusual. Not only did it start from a very high fertility level and very early in the nation's development, but it also took place long before the nation's mortality transition, industrialization, and urbanization. This paper assembles new county-level, household-level, and individual-level data, including new complete-count IPUMS microdata databases of the 1830-1880 censuses, to evaluate different theories for the nineteenth-century American fertility transition. We construct cross-sectional models of net fertility for currently-married white couples in census years 1830-1880 and test the results with a subset of couples linked between the 1850-1860, 1860-1870, and 1870-1880 censuses. We find evidence of marital fertility control consistent with hypotheses as early as 1830. The results indicate support for several different but complementary theories of the early U.S. fertility decline, including the land availability, conventional structuralist, ideational, child demand/quality-quantity tradeoff, and life-cycle savings theories.