Labor- and Capital- Augmenting Technical Change
分析企业可同时进行劳动增强或资本增强技术改进的经济，长期表现为标准增长模型，但转型路径上要素份额会变化，且政策可能产生反直觉影响。
I analyze an economy in which pro...t-maximizing ...rms can undertake both laboror capital-augmenting technological improvements. In the long run, the economy looks like the standard growth model with purely labor-augmenting technical change, and the share of labor in GDP is constant. Along the transition path, however, there is capitalaugmenting technical change and factor shares change. A range of policies may have counterintuitive implications due to their eect on the direction of technical change. For example, taxes on capital income reduce the labor share in the short run, but increase it in the medium/long run. Keywords: Economic Growth, Endogenous Growth, Factor Shares, Technical Change. JEL Classi...cation: O33, O14, O31, E25. I thank Manuel Amador, Abhijit Banarjee, Olivier Blanchard, and Jaume Ventura for useful comments. y Massachusetts Institute of Technology, Department of Economics, E52-371, Cambridge, MA 02319; e-mail: daron@mit.edu 1 I.