The investment value of a property can only be measured against other investment opportunities available to an investor. If investors can earn 4.5% by investing in government treasuries, they will demand a higher return to invest in an asset as volatile and as illiquid as residential real estate. The rate of return an investor demands is called a "discount rate."

The United States Department of Labor Bureau of Labor Statistics measures the rent of primary residence (rent) and Owners' equivalent rent of primary residence (rental equivalence). They make this distinction because a house has both a consumptive purpose and an investment purpose. The consumptive value is measured by rent or rental equivalence.

When lenders develop new loan programs, they assume borrowers are sophisticated enough to understand the product and disciplined enough to use them properly. Both assumptions are bad, and these bad assumptions caused lenders and investors to lose a great deal of money during the housing bubble.

The most egregious examples of predatory lending occurred when interest-only loan products where offered to subprime borrowers whose income only qualified them to make the initial minimum payment (assuming the borrower actually had this income). This loan program was commonly known as the two-twenty-eight (2/28).

Exotic loan financing terms took over mortgage finance in the housing bubble. As people using these loan programs began to default in large numbers, exotic loan programs all but disappeared. This left the 30-year, fixed-rate, conventionally amortized loan as the only game in town.

Mortgage interest rates are the single-most important factor determining the borrowing power of a potential house buyer. When rates are very low, a borrower can service a large amount of debt with a relatively small payment, and when interest rates are very high, a borrower can service a small amount of debt with a relatively large payment.

Borrowers are broadly categorized by the characteristics of their payment history as reflected in their FICO score. FICO risk scores are developed and maintained by the Fair Isaac Corporation utilizing a proprietary predictive model based on an analysis of consumer profiles and credit histories. These models are updated to reflect changes in consumer credit behavior and lending practices.

Volatility in real estate prices is not new to California. During the 1970s, real estate prices detached from typical valuations of three-times yearly income seen in the rest of the country. Once residents realized they could push up prices in their real estate markets to dizzying heights, they have been doing it ever since. Greed springs eternal.

A negative amortization loan is any loan where the monthly payment does not cover the monthly interest expense. Since the negative amortization loan breaks down this traditional relationship, there is a completely separate rate calculated for the minimum payment amount.

There are 3 main categories of loans: Conventional, Interest-Only, and Negative Amortization. The distinction between these loans is how the amount of principal is impacted by monthly payments. Conventional loans pay off the debt, interest only loans neither increases or decreases the debt, and negative amortization loans add to the debt.