Moment of torque In the early 20th century, famous American economist elvin fisher developed the theory of economic gain. In its book "the nature of capital and yield", first, the concept of yield is analyzed in terms of the performance of earnings, and three different types of benefits are proposed: 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. Although "toys" r "us" on Thursday is facing potential management problems, but if you can't reach a deal with endowment lifeboat, then the number of retailers would increase by 22%, nearly 8000, face "significant financial trouble". Begbies Traynor, a bankruptcy consultancy.