Life History Theory Predicts Age of First Reproduction with Economic and Longevity Factors

James Anderson, University of Washington

The age of first reproduction is known to correlate with economic- and longevity-related factors and a general pattern emerges in which reproduction timing is advanced when expected lifespan is shorter and timing is delayed with increased wealth and education. While these patterns have been considered with economic models, quantitative models based on life history theory are rare. In this paper I demonstrate that a simple life history model can generate the observed patterns. Moreover, the model contains only two parameters, one representing the rate of wealth accumulation and a second representing the rate at which reproductive capacity declines with age. The model is applied to data and illuminates implicit assumptions in life history theory that may not typically be considered in demography.