Economics has no business inside a household. People oughta leave it in the market place where it belongs.
The other day I was watching a talk by a professor on financial incentives - one of the topics he touched upon was whether we should use financial incentives to encourage kids to read (2 dollars per book, some schools are already trying it). The audience gave reasons for both sides of the debate and it was quite interesting. Point is, we are already using financial incentives for all kinds of things that feel weird (paying kids to read?). I personally don't think this is a great idea but I'm sure many people would disagree. So why not in personal lives too?
Probably got mashed up in the potential divorce court paperwork.
What I'm really curious about is how you come to negotiate such terms and how that conversation plays out, but it really wouldn't surprise me if both sides approached the marriage in rational, economic terms and enjoyed that approach.
Perhaps I feel this way because I am an immigrant and family culture is very different in my (Asian) country. I just cannot fathom such calculating behavior when it comes to relationships.