A post at the Calculated Risk blog includes the chart copied below which shows that while home prices have declined as a percent of gross development product, mortgage balances still have a long way to go.
As Jacob Goldstein pointed out in an NPR Planet Money post on this topic on June 9, 2011, a 2010 study found that de-leveraging often takes as long as the credit boom that preceded it. That study, by the husband and wife economic team of Carmen and Vicent Reinhart, concludes that the recent mortgage credit boom lasted for about a decade, and ended in 2007. If de-leveraging takes as long as leveraging up did, it could take until 2016 before household mortgage debt falls back in line with pre-bubble residential real estate values.