Government and private-lender attempts to stem the home foreclosure crisis so far have mostly focused on loan modifications or refinancing -- giving borrowers a temporary or permanent reduction in their monthly payments.

But some housing experts say the next wave of help will have to address the core problem for many homeowners: negative equity.

This camp believes that there is no alternative but outright forgiveness of a substantial chunk of mortgage debt for many people who are underwater in their homes and at risk of foreclosure.