Another factor might be the availability of work. When the Golden Gate Bridge was being built during The Depression, men lined up, just incase they needed people. When ever anyone spoke up about safety or working conditions, they were shown to the other side of the fence. So, the employers may know that they have more workers than jobs, and can act as they desire. Of course, I'm not up on the current economic conditions in China, so this may not apply, but it might be something to consider.