operating profit ebitda Central bankers' tasks are limited to keeping inflation stable and independence easier to maintain. Given this narrow mandate, the allocation of central bank decisions is limited. Moreover, it is easier to explain how the central bank's policy tools are linked to its political mandate. The value was originally derived from the special material system, the preordering movement of dissipative structure, and the "ordering energy" was the original "value". With the continuous evolution of human beings, "ordering energy" further developed into "generalized and orderly energy", which gradually became the real human value. In a word, the value is derived from the nature, and with the evolution of the human evolution, the development of the society, the development trend of value of ultimate principle is only the movement of the material world and labor of human society. First of all, the earnings of the fund in 2017 are in an uncertain environment. The first half of the market is in a period of "cash shortage". Towards the end of the year, the central bank started to fight for the "money shortage", so monetary policy eased and interbank money market rates fell. As a result, yu 'ebao's yields suddenly fell below the 4 per cent mark. Michael Zezas, an analyst at Morgan Stanley, also said the tax legislation would be a boon to the market in the short term, but may not be able to make fundamental changes. The current flattening of the us Treasury yield curve shows that the medium-term slowdown in the us economy and the recession of 2019 are not going away. A tax reform would widen the fiscal deficit, possibly in the future and exacerbate cyclical risks in the economy.