Dynamic Efficiency: Finite Horizons Matter.

This paper qualifies Weil [1989]'s according to which dynamic efficiency may fail when agents are infinitely-lived, but "disconnected" from previous ones. It is shown that finite horizons matter in the following sense: if dynamic inefficiency results when the agents have infinite horizons, then there exists a uniquelifetime expectancy aboce (under) which there is a dynamic inefficiency (efficiency). Expressed differently, horizons have to be sufficiently long for over-accumulation to arise.