In Kim Robinson's Years of Rice and Salt Book One (Awake to Emptiness) Bold and Kyu arrive in Beijing to find that in China there was a large human population. In China there was a reliance on human labor instead of animal labor, because there was an abundance of human labor available. Animal labor in China was almost nonexistant.

Some historians believe that science and technology developed in the West instead of China because China had an abundance of human labor, it wasn't in need of technology, even though it had the knowledge in place for a technological revolution to occur there.