Endogenous vs. Semi‐endogenous Growth in a Two‐R&D‐Sector Model
在两研发部门增长模型中证明半内生增长比内生增长更普遍，内生增长需要两个参数条件，并指出知识溢出是关键，政策无法提高长期增长率。
This paper contributes to the endogenous versus semi‐endogenous growth debate by establishing that semi‐endogenous growth is more general than endogenous growth in a two‐R&D‐sector growth model. It is demonstrated that endogenous growth requires two 'knife‐edge' conditions of parameters. This finding (i) is in sharp contrast to recent two‐R&D‐sector models that show that long‐run growth is endogenous, and (ii) resurrects the policy conclusion of semi‐endogenous growth that government policy is not effective in raising the underlying growth rate of an economy. The driving force of these results is knowledge spillovers between two R&D activities, which are largely neglected in existing studies.