For Canadians you can add government fees, regulations and lesser competition to the reasons this occurs. I once bought a ticket from Vancouver to London (UK)

For Canadians you can add government fees, regulations and lesser competition to the reasons this occurs. I once bought a ticket from Vancouver to London (UK) on Air Canada. Turns out I could have saved over $200 by flying via the same airline out of Seattle and connecting back in Vancouver to the exact same flight going on to London. Absurd.