In reference to the 2016 Canadian Census, the post-secondary student population was captured at their main place of residence, which is usually the home of their parent(s). Even if a student lived elsewhere while attending school (on campus for instance) or working at a summer job, households were asked to include them when completing the census.
By definition, an analysis of areas surrounding post-secondary institutions will not necessarily capture the student population who attends those institutions unless these students also lived in those areas as their main residence.
There are other ways to analyze the Canadian student population depending on the objective, the market, and data licensed. For example, some PRIZM segments represent larger student populations. Please contact your Account Manager to discuss your best options.