non profit training institute 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: Japan's industrial standard, JISK 0101, defines a car as a vehicle equipped with an engine and a control device that can still drive on land without a fixed orbit or overhead line. Full market competition will make economic activity full of vigor and vitality. Mr Draghi said the positive news about eurozone growth meant that the bank's council was "increasingly confident" that inflation would strengthen over the long term and become "self-sustaining". But he added that the current policy needed to be maintained to "maintain inflation", reaching the ECB's target of close to 2 percentage points. Data released by the American petroleum institute (API) showed that U.S. crude oil inventories fell 5.2 million barrels in the week ended Dec. 15, down from an expected 35.18 million barrels. Refinery inventories fell more than expected, while gasoline inventories rose, but were less than expected. The overall API data is good and good for oil prices. (3) monetary benefits -- increase the monetary value of assets. There are both measurable and unquantifiable benefits in these three different forms of income. Among them: mental income is too strong to measure, monetary gain is easy to measure because of the static concept of value change. Economists, therefore, focus only on actual earnings.