2. The amount of information is asymmetric. No matter what kind of tax assessment method is adopted, it is inseparable from having accurate data sources. In the process of tax assessment, we strive to fully measure, compare, quantify and qualitatively analyze the relevant business indicators, realized tax indicators and the relevant peaks of each indicator, so as to find the correct starting point. It can be seen that without sufficient data sources, it is difficult for tax assessment to achieve the expected results. In reality, we often encounter the dilemma of information asymmetry, such as tax return data and financial data submitted by taxpayers, production and operation information, enterprise accounting information and other untrue and incomplete tax-related information such as registration, bank accounts and account numbers, prices, etc. As far as the current situation is concerned, tax administrators have no effective channels or enough time and energy to obtain complex information, and can only make a targeted assessment of superficial problems such as "tax burden" reflected in taxpayers' reports. However, because the information source is incomplete or may be wrong, they can't completely analyze and find the problems, which will inevitably lead to low evaluation efficiency and large audit errors. Only by fully grasping the above information, through calculation, comparison and comprehensive analysis, can we make a more correct evaluation, analysis and accurate judgment.

The overall professional quality of tax administrators is not high. No matter from the objective needs of the actual tax management work or the inevitable trend of the development of tax collection and management work, it is increasingly necessary to cultivate comprehensive and compound tax administrators with certain quality requirements, that is, they must have certain computer operation, know enterprise management, economic theory and accounting skills. , but also master tax management, tax policy, tax inspection, statistical analysis and other related knowledge. Most of the staff engaged in tax management positions evolved from the reform of the special administrator system in a certain period of time under the condition that the original post skills were clearly separated. The business skills of this part of tax administrators are characterized by strong skill oneness, the follow-up knowledge and skills can not keep up with the skill requirements of tax assessment, and the quality of tax professionals is uneven. A considerable number of appraisers have narrow knowledge and single skills in business management, economic theory, tax management, tax inspection and statistical analysis. There are not enough professional, comprehensive and high-quality talents among tax administrators to play a leading role in tax assessment practice, which will inevitably lead to a wide range of ideas, few methods and low efficiency. Some can only complete shallow assessments such as table reading, logarithm and ticket checking in a general sense, and cannot collect, analyze and evaluate deep-seated and representative tax-related issues, making it difficult to improve the efficiency and benefit of tax assessment.