Fertility and PAYG pensions and in the overlapping generations model

This article analyses how long-run pay-as-you-go public pensions react to a change in fertility in the Diamond overlapping generations model. While it might seem well established both in academic and political debates that the decline in fertility represents a “demographic time bomb” for the sustainability of public pensions, it is shown that a falling birth rate need not necessarily cause the fall of pensions in the long run.