[throwaway2037]

    > Walkaways worked because real estate debt (in most of the US) is non-recourse debt. You leave the mortgage, the bank (or present mortgage holder) gets the property. Debt is settled.

It is rare this simple. You will likely be required to file bankruptcy, or something equally disruptive to "walk away". And, it will trash your personal credit rating. What is the incentive for banks to allow walk aways? It is very low. The administrative burden of taking ownership of a home, then trying to sell it will nearly guarantee losses for the lender. In most US states, if you cannot pay your mortgage, the bank will sell the home. Most of the time, any shortfall can be forgiven, but not easily. If there is a gain, you will be repaid, minus expenses, but this is exceptionally rare.