Final answer:
Economic development, industrialization, and the growth of manufacturing in coastal cities and SEZs have been key factors driving the substantial rural-to-urban migration in China since the 1980s.
Step-by-step explanation:
One important factor driving internal migration in China since the 1980s has been economic development and industrialization, particularly the growth of manufacturing in coastal cities and Special Economic Zones (SEZs). These urban and industrial areas offer greater employment opportunities and potential for a higher standard of living compared to rural areas. This has led to a significant rural-to-urban migration, as people move from the countryside to cities in search of better job opportunities, education, and living conditions. Moreover, China's shift from a command economy to a market economy and its open trade policy have fueled this migration trend, as the country's urbanization increased at an unprecedented rate from 17 percent in 1978 to 47 percent in 2010, marking one of the largest rural-to-urban shifts in human history.