Let me be blunt: If you are looking for fairness do not raise a family. There is nothing fair about cleaning accidents or walking a baby at two in morning. There is nothing fair about sitting through recitals that stink. Nothing fair about your one day off and someone bounces on your head at 630 am. Nothing fair about emergency room visits or parent/teacher conferences because your child is acting up.
The only fairness comes from the balance and that is not between mom and dad, that is within a parents heart. Those wonderful moments that balance out the hardships and the love that balances out the cost.
If a mom and dad are worried about fairness they should visit a widow mom of a fallen soldier and contemplate fair.
A little harsh, sorry about that.