Social security and endogenous fertility: pensions and child allowances as siamese twins

This paper analyses public pensions and child support in a model with endogenous fertility. We show that the individual fertility choice may not coincide with the social optimum, due to the existence of external effects of children on society as a whole. The market outcome without government intervention is efficient, however, as the externalities exactly cancel out in that case. if the government wants to redistribute towards the old, it cannot replicate the command optimum by merely applying lump-sum transfers, but rather needs a child allowance scheme to effectively alter the number of offspring. Finally, we analyse whether a Pareto-improving social security reform is possible. It is shown that merely reducing the PAYG-scheme cannot be pareto-improving, but the introduction of a child allowance scheme can be.