I've had occasion this last ten days to be thinking about the way housing and equity is settled in a Scottish divorce (not me! my ex is getting divorced again!)
Anyway - when I got divorced, during the boom, the calculation was easy. We had bought a house together and it had gone up in value, so he simply paid me half of the equity we had accrued over our time together and I moved out leaving him the mortgage.
Given he only married his latest wife two years ago and she moved into a house that he owned (with a mortgage) and had been paying for ten years, does that mean he owes her half of the value it has gained over those two years, or more likely she owes him half of what it has lost in the meantime?
If the latter is true, I may have come up with a perfect business model for single people trying to recoup some of the negative equity they are currently running up!!