WASHINGTON -- Would you, under any circumstances, default on your home mortgage, even if you could afford to make the monthly payments?

That's a trickier question than you might assume, according to new research from the University of Chicago's Booth School of Business and Northwestern University's Kellogg School of Management.

The study found that 26 percent of the record numbers of home mortgage defaults across the country are "strategic" -- that is, calculated economic decisions to bail out of loans by owners who actually have the money to make the payments but can't handle the negative equity they're carrying caused by local property value declines.

Nationwide, according to data from Zillow.com, 22 percent of all homeowners were in negative equity positions during the first quarter of 2009 -- "underwater" -- with mortgage debts that exceed their home values.

In some parts of California and Nevada, more than half of all households have negative equity. In a few localities, the size of the equity deficit is staggering: In the Salinas, Calif., metropolitan area, for example, the median equity for people who bought their homes in 2006 near the peak of the boom is now a negative $214,305, according to the study.

When researchers questioned two nationally representative statistical samples of households about strategic defaults, they found that moral and social beliefs play a constraining role, but negative equity and the frequency of defaults in local ZIP codes have significant contrary impacts.

Co-authors Paola Sapienza, Luigi Zingales and Luigi Guiso used interviews with 2,000 American households last December and this past March to explore the "moral and social" dynamics of strategic defaults. The two 1,000-person samples came from the Chicago Booth/Kellogg School Financial Trust Index, which monitors the level of trust households have in the financial system.

Their research not only represents the first attitudinal study of the phenomenon of widespread strategic walkaways from home loan commitments, but also has implications for federal policies seeking to limit the numbers of foreclosures -- which are on pace for a record 3.1 million filings this year, according to RealtyTrac Inc.

Among the study's sobering findings:

Moral precepts keep large numbers of financially struggling homeowners out of default, but only to a point. Fully 81 percent of household heads said they believe intentional defaults on mortgages to be "morally wrong." But that high percentage begins to crumble as negative equity grows increasingly larger. Continued...