Human capital differences across countries can appear large or small depending on measurement methods. This Reply clarifies key assumptions and conceptual distinctions across accounting approaches. Accounting-based arguments for small human capital differences are difficult to sustain. By contrast, large human capital differences are theoretically and empirically coherent. Non-accounting arguments against large human capital variation are examined and their weaknesses pinpointed. This Reply also suggests a fruitful way forward for this literature, providing a natural conception of human capital that integrates literatures on ideas and institutions with the accounting of Jones (2014).

Technological advance is often embodied in capital inputs, like computers, airplanes, and robots. This paper builds a framework where capital inputs advance through (i) increased automation and (ii) increased productivity. The interplay of these two innovation dimensions can produce balanced growth, satisfying the Uzawa Growth Theorem even though technological progress is capital-embodied. The framework can further address structural transformation, general-purpose technologies, the limited macroeconomic impact of computing, and declining productivity growth and labor shares. Overall, this tractable framework can help resolve puzzling tensions between micro-level observations of innovation and balanced growth while providing new perspectives on numerous macroeconomic phenomena.