Final answer:
U.S. productivity is greatly influenced by high labor productivity, which is the value created by each worker per hour worked. This measure has shown growth over time, indicating increased efficiency within the U.S. workforce. The correct option is 3) labor productivity
Step-by-step explanation:
A significant reason why U.S. productivity is the highest in the world is high labor productivity. Labor productivity is a measure of the value that each employed person creates per unit of their input, often expressed as the dollar value per hour that the worker contributes to the employer's output.
This includes all kinds of outputs except the output of government workers which is not sold in the market. Agricultural and manufacturing productivity contribute as well, but the primary driver is labor productivity, which has seen substantial growth over time.
For example, the index of output per hour in the U.S. has more than doubled from 1972 to 2014, indicating that workers are able to produce significantly more in the same amount of time as they did decades ago. The correct option is 3) labor productivity