In this paper, we show that the competitive equilibrium is optimal in the Uzawa-Lucas model with sector-specific externalities associated to human capital in the goods sector. Thus, these external effects do not provoke a market failure and do not provide a rationale for government intervention....

This paper devises a fiscal policy by means of which the first-best optimum equilibrium is attained as a market equilibrium in the Uzawa-Lucas model when average human capital has an external effect on productivity. The optimal policy requires the use of a subsidy to investment in human capital...