Judging from the existing research, the late Professor Ma Shuluan from the Institute of Population Studies of Nanjing University may be the first demographer in China to adopt PQLI (literally translated as "material quality of life" or "material quality of life", translated as "quality of life index" or "population quality index") to measure the population quality stock. Ma Shuluan calculated according to the data of the third population census in 1982 and compared it with foreign countries. The conclusions are as follows: 1982, PQLI of China is 77, that of India is 43 and that of the United States is 94; Moreover, the ranking of the population quality of life index of China's provinces, municipalities and autonomous regions in China is from 65438 to 0982, which is basically consistent with its per capita GNP (Ma Shuluan 1986). Wang Jun made a time series comparison of the changes of the population's quality of life index in China from 1982 to 1990. The conclusion is that the PQLI of China in 1990 is 83; From the perspective of regional differences, the high-quality population with PQLI above 80 accounts for 8 1.24% of the total population in China, and the medium-quality population with PQLI between 60-80 accounts for 18.57% of the total population in China. Only Tibet has 5 1, which is a low-quality population. And once again, it is found that there is a close positive correlation between PQLI and GNP per capita (Wang Jun Gai, Siewek 1997), that is, population quality is a function of social and economic development, and both of them complement each other at the same time. The author himself has also made an international comparison of PQLI value 1990 under certain assumptions, and the conclusion is: the world average level is 65, developed countries are 94, underdeveloped countries are 53, China is about 80, and Indian is 57. Considering the comprehensive development level of China's population quality, at least on the phenomenon level, it can be considered that the development level of China's population quality is ahead of the economic development level (Mu Guangzong, Xu Jinsheng 65433). Zhu (1994) has two main explanations for this strange phenomenon: one is that the above-mentioned "advance" phenomenon may indicate to some extent that the conversion rate of China's population quality potential and its contribution rate to economic growth are still low; In other words, the human resources in China need to be fully and effectively developed and utilized, which seems to be consistent with the social facts we have observed (Mu Guangzong 1996). Another view is that "leading" may be an illusion (Feng 1992).

Although PQLI method has many advantages, for example, people generally hope that the three indicators will reach a higher level, but the three indicators are pan-human, reflecting the "output" situation, better reflecting the welfare status of the population in developing countries, and the calculation is relatively simple and convenient. However, many scholars believe that this method has many limitations: firstly, two of the three components of PQLI reflect the health status, and only 1 reflects the education status; It seems too rough to reflect the cultural needs of the population in developing countries only by literacy rate; It is obviously too simple to reflect the quality of life of the population in developing countries only from the aspects of health and cultural level. Accordingly, some scholars have put forward some improved methods, replacing infant mortality rate and 1 year life expectancy with the index of "average life expectancy at 0 years old" and replacing literacy rate with "average years of education for people aged 25 and above" (Feng, 1992). Some scholars used "the proportion of people over 25 with secondary education or above" instead of literacy rate, and tested it with actual data, and the result was satisfactory (Zhu 1994).

Some scholars have found another way to measure the stock of population quality in China and the newly created index. Chen Zaihua of capital university of economics and business Population Research Institute (1992) used fuzzy mathematics to deal with each factor index, and used fuzzy membership function to make each factor index dimensionless and horizontally comparable, and established a comprehensive evaluation model of population quality. The results show that the quality of population in China is constantly improving, both comprehensively and in terms of factors. Structurally, the problems mainly lie in scientific and cultural quality and ideological and moral quality, and the differences between regions are also mainly in these aspects. One of the biggest defects of Chen Zaihua's method is that it is too complicated and difficult to popularize. Xia Haiyong (1992) of the Institute of Population Studies of Nanjing University also put forward a "comprehensive index of population quality". He considered the population factor, but neglected the ideological and moral aspects. Finally, he chose nine indicators to construct a "comprehensive index of population quality", namely, average life expectancy, infant mortality rate, the proportion of disabled population to the total population, total fertility rate, adult literacy rate of men, adult literacy rate of women and education level. The calculation method is to form a set of value matrix of evaluation index system through systematic cluster analysis, get the basic point data, and then calculate the "comprehensive index of population quality" to get the evaluation concept. According to the author's own evaluation, this method has good effect, wide reflection and high sensitivity. But the main question is? What's wrong with pepper? Huan? Did I send you a message on April 4th? Ben Zheng Pu He 99 1) and Jiangsu Provincial Family Planning Commission and others (1998) also discussed and put forward the "population quality index".

Because population quality itself is a rather complicated phenomenon, it is impossible to try to reveal it clearly in a way. To sum up, the author thinks that the vitality of PQLI method can not be ignored. At present, some discussions in China have not reached a consensus, and there is no new index to replace PQLI. Therefore, it is undoubtedly necessary to continue to explore new indexes, but it needs to be reminded that attention should be paid to the availability of data and the convenience of operation. Judging from the current situation, the improved PQLI method makes it more practical, accurate and practical.

Verb (abbreviation of verb) A theoretical discussion on population quality.

1992, Professor Zheng Liu once again mentioned "population modernization", which had a great influence on the population academic and practical departments. In the framework of "population modernization", "population quality modernization" has been placed in a key position (Zheng Liu1992; Mu Guangzong 1995,1999; Chen Youhua 1998). At present, the "Three Excellent Systems Project" proposed by China is a concrete measure to implement the "modernization of population quality". The so-called "three excellent" refers to eugenics, excellent education and excellent education.

In order to grasp the problem of "population quality" as a whole, the author put forward the "barrel theory of population quality" in the first half of 199 1. At the same time, Xu Jinsheng from the Institute of Sociology of the Beijing Academy of Social Sciences has put forward a similar theory. The so-called "barrel theory of population quality" is inspired by the "barrel phenomenon" often mentioned in philosophy of science, that is, assuming that the periphery of a barrel is uneven, the capacity of a barrel is limited by the shortest board. The author thinks that the problem of population quality itself and the relationship between population quality and social and economic development belong to two levels. In other words, one is the level of population quality stock, and the other is the level of development or transformation of population quality potential. The "short board effect" of China's population quality is mainly manifested in the non-intellectual quality. Therefore, only by establishing a social and economic mechanism to correctly evaluate talents and rationally develop human resources can China shape a mechanism to constantly overcome the "short board effect" and make the quality potential of the population explode continuously. Only when human resources development and population quality investment complement each other can a virtuous circle be formed. Population quality investment generally includes investment in eugenics, culture and education, health and hygiene, and investment in optimizing environment (ecological environment, working environment and living environment).