The Research Of The World’s Fertility Pattern In The Context Of Population Transition

On the basis of previous researches on fertility pattern, this paper presented the logistic function to study the world’s fertility pattern, building some indicators such as average fertility age, standard deviation, the fertility age of peak value and peak value. By these indicators, we investigated fertility pattern transition of developed regions, developing regions and the least developed regions in the past40years, found that the average fertility age and the fertility age of peak value of developed regions delayed, but those of the developing regions and the least developed regions become lower. The age specific fertility rates of all countries were generally lower and the difference between them reduced. In the developing regions and the least developed regions, modernization changed people’s fertility attitudes, expected number of birth was not realized. In the developed regions, a lot of factors driven women delay childbearing. Further study found that there was one road in the transition of fertility pattern, developed regions were in front of the developing regions and the least developed regions. The total fertility rate of2.1was a turning point, when the total fertility rate was greater than2.1, the average fertility age and the fertility age of peak value of countries and regions become lower, when the total fertility rate of was less than2.1, the average fertility age and the fertility age of peak value of countries and regions delayed. The fertility pattern transition of low-fertility countries were postponing. Low-fertility countries can be divided into two types, total fertility rate of the first type such as Sweden fixed, its fertility postponed just because the20-28year old women reduced their childbearing but older women made up for those. Total fertility rate of the other type such as Japan was declining rapidly, its fertility postponed just because the specific fertility rate of20-26years old women declined faster than other ages. The postponing of low-fertility countries would not be indefinite, when science and technology did not change and human life expectancy did improve, combining with some of Europe’s investigations, we believed that the postponement limit of the fertility age of peak value was around30years old, and the limit of the average fertility age was in the35-year-old.At the end of the article, through summarizing existing fertility theories, we presented a systematic explanation for fertility postpone phenomenon. Industrialization, modernization and urbanization as the background of this era were the most important reasons of the fertility pattern transition. Institutional factors such as economy, education, social values, population movement, legal policy and the natural environment were main reasons for fertility patterns transition, they operated through the mediating variables:age at first marriage, ability to birth, contraception, abortion which had direct impact on fertility pattern transition. We then used the data of the United Nations on the theory testing, and the results were consistent with the theoretical, although some indicators could not operate, our regressions’explanatory power were very well, as adjusted R square up to0.68.