n.
Price paid for the use of credit or money .
It is usually figured as a percentage of the money borrowed and is computed annually. Interest is charged by the lender as payment for the loss of his or her money for a period of time. The interest rate reflects the risk of lending and is higher for loans that are considered higher-risk, a relationship known as the risk/return tradeoff. Like the prices of goods and services, interest rates are responsive to supply and demand . Theories explaining the need for interest include the time-preference theory, according to which interest is the inducement to engage in time-consuming but more productive activities, and the liquidity-preference theory of John Maynard Keynes , according to which interest is the inducement to sacrifice a desired degree of liquidity for a nonliquid contractual obligation. Interest rates may also be used as a tool for implementing monetary policy (see discount rate ). High interest rates may dampen the economy by making it difficult for consumers, businesses, and home buyers to secure loans, while lower rates tend to stimulate the economy and encourage both investment and consumption .