During the Canadian census, most Canadians complete a “Short Form” which is the government’s primary source of demographic data. Some Canadians are selected at random to complete a “Long Form” which also provides information on social and economic factors. In the 2011 census, the “Long Form” switched from mandatory to voluntary. In the 2016 census it became mandatory again. What are the impacts of switching between mandatory and voluntary for the “Long Form”?