The reasonably decent performance of AC as a stock has a lot to do with the delays in the 787, and the resultant squeeze in capacity. More so than it has to do with AC actually being an efficient firm. They've managed to get quite a bit more life than I think expected out of the 320 series planes which basically have minimal carrying costs at this point.

Once the 787s arrive in reasonable numbers, I expect the stock to crater just like it did in the early 1990s when the 320-series started arriving in significant numbers.

One thing that is quite apparent these days is that most travel is leisure/discretionary. Which wasn't the case in the 1980s and 1990s when most air travel was business. So as we see the housing market pull back, it is quite likely that AC is particularly vulnerable to a loss of overall business. There's a very fine line between optimal use of capacity, over-capacity, and under-capacity. And its very hard to walk that tightrope over the long term in the airline industry.