This is the rate o short-term U. S. treasury securities, assuming there is no inflation This is the premium that reflects the risk associated with changes in interest rates for a long-term security this premium is added when a security lacks marketability, because it cannot be bought and sold quickly without losing value. It is based on the bond's rating; the higher the rating, the lower the premium added, thus lowering the interest rate. This is the rate on a treasury bill or a treasury bond. This is the premium added to the real risk-free rate to compensate for a decrease in purchasing power over time