This paper studies the origins and consequences of international technology gaps. I develop an endogenous growth model where R&D efficiency varies across countries and productivity differences emerge from firm-level technology investments. The theory characterizes how innovation and learning...

We explore the possibility that a global productivity slowdown is responsible for the widespread decline in the labor share of national income. In a neoclassical growth model with endogenous human capital accumulation a la Ben Porath (1967) and capital-skill complementarity a la Grossman et al....

Evidence for the United States suggests balanced growth despite falling investment-good prices and less than unitary elasticity of substitution between capital and labor. This is inconsistent with the Uzawa Growth Theorem. We extend Uzawa.s theorem to show that introducing human capital...