Measuring Couple's Fertility Change in Process of the New Transition in Japan, with Special Attention to Effects of Marriage Delay and Educational Upgrading

Ryuichi Kaneko, National Institute of Population and Social Security Research, Japan

Japanese fertility decline had been accompanied with relatively stable marital fertility until around 1990. However certain decline has been witnessed during 1990’s. Does this indicate onset of new phase in the fertility transition? This paper is to attempt to reconstruct history of Japanese marital fertility along with 48 years of wife’s birth cohort by age and birth order using results from six national representative fertility surveys expanded over 25 years. Decomposition of fertility reduction into effects of exogenous factors such as marriage delay on marital fertility is inevitable to estimate reduction from couple’s behavioral change. The logistic regression framework is applied for this purpose. Some visual techniques such as the Lexis mapping are employed to understand what is happening in the marital fertility. With decomposition, they revealed detailed process of onset of marital fertility reduction, indicating who, when, which birth order, and how much change in reproductive behavior is initiated.