So, how did you spend your weekend? If you were in an area that was bracing for a hurricane my guess is that you weren’t cuddling up with your significant other. If you were in an area that had a tropical storm warning, though, you might have been doing just that. Birth rate data suggests that while tropical storm warnings increase sexual activity, hurricane warnings put a damper on the mood.*
Recent economic research using data collected from 1995 to 2001 finds that areas in the Atlantic and Gulf coast counties in the USA that received tropical storm warnings experienced a post-storm baby boom – with an average increase in the birth rate of just over 2.1% nine months following a 24-hour tropical storm warning. Hurricane warnings had the opposite effect with an average decrease in births of 2.2% following a 24-hour hurricane warning. With an average number of births in these coastal counties of 746 each month, these numbers translate into either 16 more babies conceived in tropical storms or 16 fewer babies conceived in hurricanes.
Almost all of this post-storm fertility effect, both on the up and down side, comes from couples that already have at least one child.
You can see why this might be the case. Many people in hurricane warning areas this weekend would have spent their time either preparing for the storm and the aftermath or getting the hell out of the area; not very romantic sleeping on your in-laws’ sofa wondering how your house is holding up. Tropical storms require less preparation and less evacuation. In fact, with everything shut down there isn’t much to do at home except wait; might as well make good use of the time.
So, can we expect a post-Irene baby boom? Not in any of the areas south of New York state that spent the preceding days preparing for a hurricane and evacuating; those areas are likely to experience a baby bust. In the areas further north, though, we might just expect to see a resurgence in the popularity of the name Irene in about nine months.
* Evans, Richard W. ; Yingyao Hu; and Zhong Zhao (2010). ”The fertility effect of catastrophe: U.S. hurricane births.” Journal of Population Economics Vol (23): pp. 1–36