revenue and net profit The accounting income follows the historical cost principle and the matching principle, which is conducive to the objective reflection of the business management responsibility of the enterprise management authorities. But, due to the historical cost principle inherent defects, especially according to the present value of revenue and expenses by historical cost line, makes the calculation of accounting earnings lack of inner logical unity, and the matching principle is difficult to carry out, so that the book value of assets can not reflect its real value, cost cannot be fully compensated. And the economic benefit is measured in the current value, which reflects the actual value of the asset, which is beneficial to the full compensation of the cost. If these measures do not satisfy his base, Mr Trump still has the last option, which the Roman emperor and other dictators have long used in difficult times at home. That is to say, he can "swing the dog" by making external threats or launching foreign military adventures, thereby dispersing his supporters from what he and republican lawmakers have done.