Why do so many houses end up abandoned?

So I have a couple of ideas on the above question.....

But as I've never seen abandonment on any scale here, or on a similar scale in the U.S., that I can personally recall, I was curious about why and how it happens [[has happened) to the degree that it does?

So to share one supposition, its my understanding that under U.S. law one can abandon a mortgaged property to the lender and then just walk away from the mortgage, is that right?

I know you can't do that under Canadian law, where if you default, and the bank sells your home for less than you owe, you still owe the bank the difference [[the debt is not discharged by merely surrendering the property).

I would imagine, if I've got that right, that this accounts for some difference in 'abandonment' levels.

Though I would wonder why a lender ending up w/such a home wouldn't sell it to someone as a going concern.

Beyond that, however, I still find it difficult to fathom.

I assume, that many abandoned home did not in fact have mortgages on them.

So even if one couldn't afford to pay the routine bills, or just wanted to move; even if the home was low in value, I'd assume you'd want a clean sale to get whatever money you could out of it.

I would equally assume any buyer would either fix-up or demolish rather than just watch a property rot, and value erode.

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I can think of only one other Canada/US difference that might bear on this, which is that Canada's cities tend to more....hmmmm, invasive about property standards management. ie. [[many Canadian cities will not let your lawn get overgrown, they will warn you once, then mow it for you at 10x market price; don't pay and they add it to your property tax bill, don't pay that, and lose your home).

This sort of intervention would likely diminish any 'abandonment' value.

However, even if that makes some small difference; I wouldn't expect it to account for the scale of abandonment in the Detroit area.

Thoughts?