btg:
Good points all.  It is noteworthy that the experts who lecture us on the gain from mass refugees' immigration never discuss the solid option of a low population density economy.  They hold fast to the creed of population growth =economic growth, omitting the key mediating factor of population productivity.  In today's Canadian economy, that productivity depends crucially on high literacy in English or French.  The current pace of Syrian refugees into Canada means that many of these people may not receive the education necessary to make them fluent in English or French: the country does not have sufficient dedicated teachers and schools to meet the need.  The current mass immigration of refugees from Syria and Africa is sowing an underclass phenomenon that will haunt Canada for a very long time if not forever.