Most of workers of the factories in eastern China are from the inland area. As the economy develops recently years, many workers find jobs locally and don't come to the east factories. The big labor shortage happens and workers have many choices between the factories. To have enough skilled workers, the factories are racing to provide competitive conditions.
A want ad at the bus station near a factory district, offering the following treatment:
Wages: $700-1000/month,
Additional bonus and social security
Same treatment for men and women
Free accommodation, air conditioner, TV, water heater in the room. Several workers share a room as usually and a separate room for a couple
I spend most of time at factories and know it is true. And many factories provide free travel on holiday as the welfare.
Eastern coastal area is most developed in China, and the government is better at protecting labor rights and benefits. The department responses quickly to labor dispute and the factories will be cruelly punished if they invade workers' rights.