关键词: 退休年龄, 生育数量, 隔代抚养, 内生生育模型

Abstract: China has a strong intergenerational parenting culture, but there is no consensus on whether delaying retirement will inhibit fertility by crowding out intergenerational parenting time. By constructing an intertemporal iterative model of endogenous fertility, intergenerational parenting and pension burden related to delayed retirement are introduced to analyze and simulate the sequential game process of retirement age and fertility under the goal of maximizing individual utility. Under the pay-asyou-go system, retirement age and fertility have an inverted U-shaped relationship; under the fund accumulation system, there is a monotonically increasing relationship. Fertility supporting measures can delay the inflection point of the retirement age, thereby expanding the space for the parallel alignment of the two policy goals of delaying retirement and encouraging fertility, and increasing fertility when the peak is reached, but will not change the relationship between the two. Thus, it is the appropriate time now to introduce a delayed retirement policy, which not only has less negative impact on fertility, but also improves individual utility, but should adopt a gradual postponement approach and pay careful attention to its possible negative effects.