In 1988 Wu met with the curator of the East Asian Studies department at the Hoover Institution at Stanford to explain his interest in studying China's network of forced-labor prison camps. Wu did not have academic experience in social studies, only that of a geologist, but his stories about his time in the camps intrigued the curator, who invited Wu to pursue research as a visiting scholar. From that time on, Wu started compiling a catalog of the labor prison camp system within mainland China. Known in China as the "laogai", which translates as "reform through labor", Wu eventually published "Laogai: The Chinese Gulag" in 1992. In the early 1990s, Wu made several trips into China in order to gather the evidence needed to prove the existence of the labor camps to the outside world — part of this involved visiting various camps and secretly recording images in photo and video.