can vegetable oil be substituted for olive oil This sharp reversal contrasts with the flattening of the previous yield curve. Then the interest rate theory of the loan is the interest rate theory of neoclassical school, which is proposed to correct Keynes's theory of "liquidity preference". In some ways, the theory of interest rate can be regarded as a synthesis of classical interest rate theory and Keynesian theory. After August 1987, for example, as the dollar fell, people rushed to buy sterling, the high-yielding currency, which rose from $1.65 to $1.90 in a very short time, up almost 20%. In order to limit the rise in the pound, the UK cut interest rates for several consecutive times between may and June 1988, falling from 10% to 7.5%, with the pound falling every time it cut interest rates. But the pound began to pick up again after the bank of England was forced to raise interest rates several times as the pound weakened too quickly and inflationary pressures increased. In 1946, the famous British economist J.R. hicks, in value and capital, developed the concept of income into a general concept of economic gain. He argues that the real purpose of computing revenues is to make people aware of the amount of money they can spend without making them poorer. Accordingly, he gave a generally accepted definition of "the maximum amount of consumption that a person can spend at the end of the term, at the same level of prosperity". Hicks's definition, though primarily for personal gain, applies to businesses as well. In the case of the enterprise, according to this definition, the enterprise income can be understood as the maximum amount that can be allocated in the enterprise cost accounting period under the same amount of capital at the end of the term and the beginning of the period.