Joshua Gans and I have a few papers showing that the timing of births responds to financial incentives, lucky dates, inauspicious dates, and even obstetricians’ conferences. But perhaps we should be relieved to know that parents aren’t perfectly strategic.
Suburban Legend: School Cutoff Dates and the Timing of Births
Stacy Dickert-Conlin & Todd Elder (Michigan State University)
Many states require children to reach five years of age by a specified calendar date in order to begin kindergarten. We use birth certificate records from 1999 to 2004 to assess whether parents systematically time childbirth before school cutoff dates to capture the option value of sending their child to school at a relatively young age, thereby avoiding a year of child care costs. Testing for discontinuities in the distribution of births around cutoff dates, we find no evidence that the financial benefits influence the timing of birth. Similarly, we find no systematic discontinuities in average mothers’ characteristics or babies’ health outcomes around cutoff dates. Timing in the neighborhood of school cutoffs occurs only when the cutoffs coincide with weekends or holidays, which may have implications for recent research that assumes birth dates in the neighborhood of cutoffs are essentially randomly assigned.
One plausible explanation is that parents aren’t very forward-looking. But another (which Dickert-Conlin and Elder discuss) is that high-income parents are increasingly holding their children back a year (“redshirting”), so the option value of being able to get your child into school a year earlier is pretty low. The available evidence seems to suggest that on average, redshirting your child is a mistake – but that doesn’t stop it happening with increasing frequency.