[Interesting date indicator in original.] From this it looks like people just plan to have their births on Valentines Day. Unlike other days where Andrew Leigh and I found birth timing effects (April 1 and Feb 29, for instance), it is harder to come up with a theory for this but I’m happy for people to try in the comments. That said, I can’t help but wonder if doctors were scheduling timing that day to make sure they weren’t interrupted in the evening or could take a quieter Feb 15.
In other Valentines links, a trembling lips equilibrium and every economics model recalibrated for relationships.