Wow, this is very interesting to me. My wife and I have always had 100% merged accounts/finances, and we don't even talk about who makes more, we consider both our incomes as "the income." I never worry that she's going to overspend on anything, nor do I ever feel the need to justify anything that I buy. If something is going to be a big purchase, we discuss it. Not because of the need for "permission" to spend the money, but because we have a certain amount each month that we consider to be usable for such things. If one of us needs to buy something expensive, the other may have to push off their own purchase a month. We simply communicate a lot about our finances.
Now you're telling me that because I make more, I need to put my wife on a stipend, and she needs permission to spend? I have so much to learn!