...being sold at desperation prices in large numbers by their owners and repossesors, they compete "unfairly" in the house market in your neighborhood. If the amount you owe on your home exceeds the market price, you're trapped and can't get out. It's called an "upside down mortgage".

This is the situation here in South Florida, where people can't move out the area or even to a new neighborhood because what they can hope to get for their house is a lot less than what they still owe on it. Those whose houses are paid off, or nearly so, can sell and leave, but they have to drop the price way down to move it, and the value of the house as an investment (probably the only investment many families have) evaporates. The result is that in an area desperate for new housing and filled with abandoned homes and dropping property values, home sales have plummeted.

It's sort of the situation Vandaleur found himself in Bester's "Fondly Fahrenheit". He couldn't sell his murderous android, but it was too valuable to just abandon.