AbstractsMedical & Health Science

Abstract

In this paper, my main purpose is to find out the relations between male total fertility rates and female total fertility rates. The basic idea of doing such a research is from the previous researches available, from which I see big potentials in the field of male fertility research. The lack of male fertility data has been keeping researchers away from doing male fertility research. Little work has been done on male fertility researches compared to that of female. Throughout previous literatures, the relations between male and female fertility is an important and major topic been discussed by demographic researchers. We pay attention to the relations between the two fertilities because it will help us to learn the differences between male and female fertility pattern, as well as male fertility transition model. Since the present fertility transition model and theory are both based on female fertility, we need to know whether they are also applicable to male fertility (Zhang, 2011). In recent years, some data sources such as the United Nations Demographic Yearbook have made male fertility data available, which enable us to predict more accurate relations between the two fertility rates. My hypothesis that male total fertility rates are of linear relations with female total fertility rates is based on the research achievements of Paget and Timaeus in 1994, who believed that the male standard fertility schedule could be expressed by a linear model of female standard fertility schedule. In order to find out the relations between the two total fertility rates, I collect data of male fertility rates and female fertility rates of as many countries as I could. Most data are from the 2008 demographic year book of the United Nations. I made attempts of four difference regression models. The first one is an extremely simple linear regression model that regressing TFRm (male total fertility rates) on TFRf (female total fertility rates). The first regression model is rough, but it gives me confirmed results that a linear model is possible. Through further analysis on outliers of the first regression, SR (sex ratio) was regarded as an important omitted variable. The second regression model improves a lot by including SR as a second independent variable. When SR included, the value of R-squared is about 0.889, the regression results are better. The next important process is a series of simulation analysis, which aims to test the effect of SR on TFRm and the effect of Am (age structure of men) on TFRm respectively. The simulation analysis provided four important conclusions. Firstly, the effect of SR on TFRm will become larger as the fertility rates increase. The effect of SR on TFRm is stronger for higher fertility rates population. Secondly, when sex ratio is in a narrow range, a linear form of SR is acceptable, while for a large interval of sex ratio, SR should be in a curvilinear form. Thirdly, since the realistic interval of SR is not narrow enough, a curvilinear form of SR is preferred in the regression model. Fourthly, Am…