The Parity and Factor Strata of Fertility Decline: Layer Decomposition Analysis of Reproductive Life Course Transition in Japan

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

Fertility rate is sum of the probabilities of having child by birth order, and each of the probability is composed of some structural and behavioral factors such as marital status and reproductive behavior of married couples. Effects from some socioeconomic factors on fertility change by way of those intermediate factors are major concern. All of those phenomena should be observed amongst the age and time space to understand what happened to humans which is life course being. Fertility change is, therefore, viewed from numerous dimensions. Lexis mapping serves as a functional screen to express multi-dimensional changes in fertility if it is used with techniques of the decomposition. I analyze the fertility decline in Japanese female cohorts using the logistic regression framework to decompose the probabilities’ change into effects from the factors such as marriage delay or educational upgrading. They revealed detailed process of fertility reduction.