PRs who want to keep their status have to live in Canada and do their taxes in Canada (some will pay taxes in Canada, some will not). Paying taxes on Canada depends on where their money is coming from and the country of origin. If they receive a pension from the home country, they would have to declare that in the Canadian taxes, but it depends on the international accords between countries if they also pay taxes in Canada (in addition to home country taxes, which, of course, depends on the home country). Some countries have agreements with Canada so that their Citizens don't pay double taxes. You would have to check and see what the rules are in your home country.