I think this is usually the big talking point.
Ultimately, there has to be a certain amount of trust involved (and self restraint). Plus, there’s things like house purchases. If she buys 3 ridiculous cushions for the sofa… Is that her purchase, or a joint one?
Her argument is… If it were down to me, the house would be bare (she isn’t wrong).
My argument is… Do we really need those ridiculous looking cushions that no one likes?
But at the end of the day, I’m sure (well… 90% sure), she’s being that stuff to make our home a better place for us and the kids, and that she doesn’t have a cushion fetish.
If one of us wants to buy something particularly expensive (or more expensive than your every day things), the other will try and be a little more cost conscious that month.
Also, if we want to buy big ticket items, we could look at selling something first (this usually applies to me buying Apple equipment every year…).
I don’t think it would work for people who want to keep a strict tally of whose spent what, because it would indeed cause too many arguments, and you’d be better off with “your money is yours, and mine is mine” etc.
But for us, it works well.
Note - We put all of our spare cash into savings at the START of the month (based on the projected outgoings that month). This generally makes us more inclined to not spend too much, because we don’t want to take money out of the savings.
Second note - Back to the initial discussion - How would you “split” the money each month if one of you was part time and earned less (especially due to childcare, and therefore, not exactly your fault?)
To say that person has less money to spend that month would be unfair, so in my opinion, it’s 50/50 or it doesn’t work.