We’d tried everything the parenting books and blogs suggest to get Squeak to use the toilet. We were coming up with a Big Fat Zero…until I abandoned the parenting advice and tested out an economic theory instead.

Squeak will be three years old next month, and he’s nowhere near potty trained. I might have conceived both my kids at the same time, from the same set of eggs and sperm, but when it comes to potty time, they couldn’t be more different.