Following up on Valentine’s Day and April Fools, a journalist was asking about April 15: Are there fewer babies born on Tax Day than on neighboring days?
Let’s go to the data:
These are data from 1968-1988 so it would certainly be interesting to see new data, but here’s what we got:
– April 1st has a lot less
– Maybe something going on Apr 15 but not much, really nothing going on there at all.
– A lot less on vacation holidays such as July 4th, Labor day,etc.
– Extra births before xmas and between xmas and New year’s, which makes sense: the baby has to come out sometime!
– Day-of-week effects were increasing over the years.
But, really, nothing going on with April 15th. April Fools is where it’s at.
I just don’t think tax day is such a big deal. It looms large in the folklore of comedy writers and editorial writers, but for regular people it’s just a pain in the ass and then it’s over, not like, “Hey, I don’t want my kid to have an April Fools birthday.”
Maybe fewer babies are conceived in the week before tax-day?
Then again, given the variability in gestation, not sure how amenable this hypothesis is to analytical attack.
This article suggests that less than 10% of tax returns are filed on the last day so the signal would be weak no matter what.