My answer to you is largely in the above answer to Marco's comment.  But yeah, it's complicated - but a doom-focused approach to the situation seemed a better fit to ET than a personal psychology one.  And I'm much clearer about my doom anxieties than I am about my other psychology problems. :-)

Oh, and another angle on that comment.  Should global civilization collapse, Japan seems like it would be in a bit of a quandary.  On the one hand, its present population is simply not sustainable from local production, especially given the global collapse of world fisheries underway.  On the other hand, the Japanese government has been FAR more forward looking, and willing to adapt to obvious problems facing it on the level of macro-economic structure, than has that of the USA.  So, it has its strengths and weaknesses a collapse scenario.

However, as much as they like foreigners now, I wonder how that would change, or not, should things turn ugly.  I also wonder what the heck I'd end up doing, once teaching English/teaching in English is no longer a viable option.

So yeah, I guess doom anxieties play a bit of role in this decision as well, though as with savings, I can't really make up my mind.