Score contribution per author:
α: calibrated so average coauthorship-adjusted count equals average raw count
Several econometric issues in the estimation of fertility equations with panel data are addressed in this paper. The most interesting is the truncation of the error term in a number-of-children equation arising from the fact that the number of children cannot fall over time. It is shown that this generates a "ratchet" mechanism under which the probability of having a child drops suddenly following a birth and then gradually rises again until another birth occurs. Estimates are provided with the National Longitudinal Survey of Young Women.