I would say that we're not even at a user-pay model here in Canada, because there is revenue that is taken from the industry that is not reinvested. The first example is the ground rent. The second example is fuel excise tax.
If you look at the U.S., all amounts that are taken from the industry are put into a trust fund that is reinvested in infrastructure. This is more like a real user-pay model. It's taking all of the charges and fees from the industry and reinvesting them in industry. That's number one.
Number two is that some people think air travel benefits only people who travel. In fact, in a globalized economy like Canada's, a lot of communities rely on air travel for tourism, immigration or trade. There is definitely a public aspect to air travel that justifies government support for the infrastructure necessary to enable it.