生育政策、生育意愿与初育年龄

Fertility Policy,Fertility Desire and Age at First Birth

在当前低生育率与老龄化叠加的人口新形势下,提高育龄女性多孩生育意愿对于改善人口结构性矛盾,充分释放生育政策效果至关重要。就多数中国家庭而言,生育一孩是基本需求,而多孩生育意愿则会基于一孩生育经历进行决策。初育年龄作为一孩生育终点和多孩生育起点,势必会对多孩生育意愿产生影响。为此,本文构建含有生育政策(数量和时机)和初育年龄的离散生命周期模型,深入分析初育年龄与多孩生育意愿之间的关系,同时探讨生育政策调整、生育机会成本和养老偏好对关系变化的影响。通过理论分析和实证验证发现,意愿生育水平与初育年龄间呈先降后增的U型关系。放松生育数量限制的边际效应递减,并且女性受宽松政策影响的育龄期长度增加有助于提高多孩生育意愿。此外,初育年龄对生育意愿的影响在低生育机会成本和偏好社会养老的女性中更为突出。高生育机会成本以及偏好社会养老保障会对多孩生育意愿产生“挤出”效应。故本文认为应针对不同初育年龄女性提供系统化、差异化的生育配套政策,以期通过提高各类女性多孩生育意愿来缓解内生性低生育率压力。本文结论为建立生育支持体系,实施积极应对人口老龄化国家战略提供参考。

In the new era,China’s population development is facing profound and complex changes.Low fertility rate is becoming one of the major risks that affect the balanced development of population,and society of aging with fewer children has become a new normal for China.The government has always attached great importance to population development.In order to adapt to the new demographic changes,China’s fertility policy and relevant supporting measures have been constantly adjusted and improved.However,the current stage of low fertility rate is no longer simplified policy-oriented,but complex endogeneity-oriented.Without actively exploring the reasons for the low fertility desire for more children,it is less efficient to solve the problem of low-fertility by implementing fertility policies only.As the age at first birth is the end of one child birth and the start of multiple births,the delay of first birth of children will inevitably affect the desire for more children and the effectiveness of fertility policies.In view of this,based on the previous achievements,this paper constructs a discrete life-cycle model with the age at first birth and fertility policy to explore the effect of age at first birth on fertility desire.At the same time,the heterogeneous effects of the age at first birth on fertility desire under different fertility policies,fertility opportunity costs and pension preferences are analyzed.Firstly,this paper reaches a conclusion that there exists a U-shaped relationship between fertility desire for more children and the age at first birth through building theoretical models and performing numerical simulation.It shows that both the early and late childbearing women for the first birth have higher fertility desire for more children than others.Secondly,the more relaxing limits on number of children,the higher desire for more children among childbearing women.However,the relaxation fertility policy has a diminishing marginal effect,while it has stronger effect on women who have experienced early motherhood.Taking the timing of relaxation of birth policy into account,we find that the less time affected by the relaxation of birth policy,the smaller enhancement of fertility desire for more children among childbearing women.Moreover,the fertility desire for more children among women with different ages at first birth can be influenced by both the fertility opportunity cost and the pension preference.Although the fertility desire for more children can be decreased by increasing the fertility opportunity cost,the delay of age at first birth has a positive compensation effect.Since the income effect of the current social security contributions can be difficult to offset the cost of having children,the enhanced pension preference will ultimately weaken the desire for more children.Finally,this paper uses the data of China General Social Survey(CGSS)in 2010,2012-2013,2015 and 2017 to verify the theoretical conclusions.The empirical analysis results indicate that there is a U-shape relationship between fertility desire and age at first birth,and the turning point of this relationship is 27.36 years old.This conclusion is still robust in the case of replacing samples and dependent variables,and considering the endogeneity of age at first birth.Moreover,the influence of the age at first birth on fertility desire for more children is more significant for women in areas with relaxed fertility policy and with lower fertility opportunity cost and higher pension preference.Accordingly,the policy implications are summarized in the following three aspects.(1)Increasing the desire for more children is not only a stage problem in the period of childbearing,it can make a sustain effect on each stage in the whole life and vice versa.Therefore,it is necessary to take the age at first birth as the start to make the decision for having more children from the perspective of the whole life-cycle.(2)The design of fertility policy should fully consider the choice of age at first birth,and supporting measures to reduce the fertility cost should be formulated based on the needs of women with different ages at first birth.(3)The fertility desire for more children can be recovered by reducing the fertility opportunity cost and increasing the return on pension investment,and thus the risk of low fertility is weakened.This paper makes three contributions to existing literature.(1)Paying more attention to the impact of the age at first birth on fertility desire for more children,this paper takes the age at first birth into theoretical and empirical models,and gets the U-shaped relationship between them,which enriches existing research conclusions.(2)Both considering the quantitative and timing effect of fertility policy on fertility desire at different ages at first birth,this paper makes up for the shortage of existing literature that only focus on the former.(3)Based on the choice of the age at first birth in the whole life-cycle,this paper explains why women are most affected by the age at first birth from the perspective of fertility opportunity cost and pension preference.And this provides a basis for formulating a differentiated fertility support system to meet the needs of early and late childbearing women for the first birth,reduce fertility costs and improve fertility desire for more children.