Relaxing the Biological Clock: Can More Time Reduce Fertility?

Egg freezing relaxes the biological deadline associated with female fertility and is widely viewed as an empowering technology expected to increase lifetime fertility. This paper challenges that intuition. We develop a finite-horizon dynamic stopping model in which fertility initiation requires the simultaneous alignment of multiple, imperfectly persistent dimensions, including partnership quality, economic conditions, and personal readiness. Initiating childbearing is irreversible and occurs only when the joint realization of these evolving states exceeds an endogenous reservation threshold. By lowering the hazard of irreversible infertility, egg freezing increases the continuation value of waiting and raises this reservation standard. Individuals optimally become more selective. However, the technology insures only against biological decline, not against partnership instability or the tightening of other age-dependent constraints. When these dimensions do not improve with age, greater selectivity can delay initiation and reduce the probability of crossing the threshold within a finite horizon. As a result, relaxing the biological deadline can reduce fertility initiation and expected completed fertility in a non-empty region of parameters. We derive formal propositions and discuss empirical implications.