by Calculated Risk on 5/05/2009 09:47:00 PM

There is substantial disagreement on the number of homeowners underwater (they owe more than their homes are worth). At the end of 2008, American CoreLogic estimated there were 8.2 million homeowners underwater.

Zillow.com is now estimating 26.9 million homeowners with negative equity.

From the WSJ: House-Price Drops Leave More Underwater

Real-estate Web site Zillow.com said that overall, the number of borrowers who are underwater climbed to 26.9 million at the end of the first quarter from 16.3 million at the end of the fourth quarter.
...
Moody's Economy.com estimates that of 78.2 million owner-occupied single-family homes, 14.8 million borrowers, or 19%, owed more than their homes were worth at the end of the first quarter, up from 13.6 million at the end of last year.

This is a substantial difference. Apparently Zillow assumes that borrowers with HELOCs have drawn down the maximum amount, and I suppose they use their house price software. My guess is Economy.com's estimate is closer.

No matter - the number is huge. And many of these borrowers are in danger of default if they experience a negative event (death, disease, divorce, unemployment, etc.)