The authors studied the problems in China according to the standard values of some countries in the same stage of development (if possible), to compare the differences between China and other countries in some aspects, including population growth, urbanization, agricultural employment ratio, real estate of wealth income, corporate taxes and other costs, and household income and consumption during change of population growth structure, dual structure transformation and other processes; from the differences, the authors estimated the possible losses of national economic consumption demand, income of residents, and GDP output caused by misleading policies and systems, including economic growth determined by the long-term process of population growth 20 years ago, population missing urbanization, and the cumulative effects of these various economic losses. In terms of analytical tools, based on an analysis of China’s economic development process, factors and impact chains, the authors built some simple mathematical models to explain in a logic way the relationship between insufficient economic consumer demand and overproduction and the slower economic growth. It is not only the assumption of the mathematical relationship, but also the proof that the change of some demographic and other factors may change other economic factors. Although it may be imperfect and relatively simple, we intend provide a possibly practical and explanatory analytical thinking, scope, method, and logical framework for studying the economic downturn in China. test