"Mao disliked greatly the economists". His job protected him from Mao's policies. "Mao disliked greatly the economists - especially economic professors from America," Zhou said in an in interview. "By that time, I had shifted to the line of language and writing ... If I had remained in Shanghai teaching economics, I think I certainly could have been imprisoned for 20 years."
Source : http://www.aljazeera.com/news/2018/01/zhou-youguang-google-honours-today-180112133907283.html