turn on voice activation 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: The basic economic unit of society in the primitive society of the clan, tribe, slave owners in the slave society, feudal society's family and the manual workshop, after the evolution of the form of this modern form in a capitalist society was born enterprise. Most western interest-rate determinism focuses on the analysis of supply and demand comparisons, arguing that interest rates are a price. The difference lies in what supply and demand determines interest rates. For example, Marshall's real interest rate theory emphasizes the real factors of non-monetary factors - productivity and the role of economy in determining interest rate decisions. Productivity is expressed by marginal propensity to invest, and the marginal propensity to save is expressed. 5. Accounting earnings depend on the reasonable proportion of income and expenses during the period. Costs that are not associated with the current period should be incurred as assets to be transferred for later periods.