Originally Posted by
TheBOSman
As the yen devalues, other than fuel costs (which are priced in USD across most of the world to the best of my knowledge), the costs for JL and NH devalue as well, as most of their costs are in yen. For US carriers, they are selling in yen but paying much more of their costs in dollars, so their costs aren't devaluing at a similar rate even though revenues are. DL and UA have both blamed some of their shortfalls in revenue on the declining yen as both have more Japan service than AA does.
I accept what you say but won't the lower Japanese costs actually be offset by increased fuel bills, due to USD pricing? I don't think you can brush this aside, particularly for long routes like this. And the Yen may be at a four year low but it is not historically low. I certainly recall getting more Yen for my Dollar when I was staying in Tokyo about 12 years ago!