Endogenous fertility and modified Pareto-optimality

In a world of endogenous fertility, where the number of descendants is an integral part of the economic allocation, the traditional concept of Pareto-optimality cannot be applied any longer: the number of individuals to be present on earth may vary between any two allocations we wish to compare. Therefore, the concept needs to be modified in order to give new life to the discussion of economic efficiency. This work introduces a straightforward variation of the Pareto-principle and characterizes the optimality of economic allocations according to this concept. It is shown that some of the well-known traditional results on intertemporal optimality do no longer hold. In particular, lump-sum tax instruments (or the rearrangement of initial endowments) are no longer a sufficient tool to achieve efficiency. Received: March 2003, Accepted: September 2005 This work has greatly benefitted from comments by Oded Galor, Karl Shell, Vasco Santos and an excellent anonymous referee. Many thanks to the Editor of this Journal for providing an impeccable refereeing process. Support by the European Union via the Human Capital and Mobility Grant #ERBCHBICT941218 is gratefully acknowledged.