Productivity and the Sources of Growth

A worker in one country can produce ten times what a similarly hard-working worker produces elsewhere not because of effort, but because of tools. Labor productivity means output per worker, usually measured as real GDP divided by the number of people employed. If a country's workers have more and better machinery, more schooling and skills, and access to superior technology, each hour of work turns into far more output. Effort matters at the margin, but across countries the gap is almost entirely explained by capital and technology, not willpower.

Physical capital, like factories, trucks, and computers, lets a worker produce more with the same two hands. Human capital, the skills and knowledge built through education and training, lets workers use tools more effectively and solve problems machines cannot. Technology, meaning better methods and inventions, lets the same capital and labor produce more output than before. These three combine: a tractor is physical capital, but a farmer trained to use GPS-guided planting is applying human capital, and the GPS software itself is technology.

Capital accumulation alone runs into diminishing returns: each new machine added to a worker who already has nine adds less output than the one before, so growth from capital investment alone eventually stalls. Sustained growth needs technological progress to keep raising what each unit of capital and labor can do. This is why productivity growth shifts both the production possibilities curve and long-run aggregate supply outward together: more can be produced with the same resources, which is the real-side counterpart to the demand-side stabilization tools covered earlier in the unit.