The article discusses new mortgage contracts designed to prevent borrowers from defaulting when their loan balance is higher than their home's value. By adjusting the balance automatically when house prices drop, these contracts discourage default but may lead to early repayments in low-price areas. However, high borrower satisfaction with homeownership or rental options can reduce early repayments. Contracts with penalties for early repayment in high-price areas are not effective. For typical foreclosure costs, these adjusted contracts are better than traditional fixed-rate mortgages when interest rate spreads are around 50-100 basis points. The benefits increase with borrower satisfaction from homeownership. The study used American options pricing methods to analyze these contracts and found specific conditions where they are advantageous.