The only reason these capitalization ratios are sustainable is if there is a lot of home value appreciation expectation, appreciation above and beyond inflation that is. (financialsamurai.com)
However, even conservative estimates are calling for 20 % home value appreciation over the next three years. (flagstonemortgage.com)
This can occur via the principal being paid down, via home value appreciation, or both. (ourvalleyhomes.net)