I'm afraid I agree with the recent posts at least. Tokyo and Singapore have different forms of homogeneity, but the word fits both (and many other places for that matter). Singapore is a
much smaller country -- about 1/20th Japan's population and about 1/500th Japan's land area -- so homogeneity in several forms is impossible to avoid. (The whole country is only about 1/45th the size of the Kanto region as another point of comparison. It's small!) Singapore is "the world's only shopping mall with a seat at the United Nations," and unfortunately
there's some truth to that.
Does your or your spouse's employer offer the opportunity for an overseas assignment posting? That'd be great.
Another financial consideration that comes to mind is social security (government pension) and other parts of social insurance (disability, survivor's). Japan has such a system, and presumably you've been contributing to the Japanese system (national and/or employees' system) for several years already. It's not the world's most
generous system, to be sure, but you've contributed into it, probably quite a lot at your income levels. As I understand it, under present law at least your contributions to date would yield nothing if you make no further contributions. You haven't met the minimum vesting period, as far as I know. You'd also fall out of disability and survivor's insurance. Work in Singapore wouldn't count toward the minimum vesting period since Japan and Singapore don't have a social security treaty. (Singapore doesn't have social security treaties with anybody.) Work elsewhere, in a treaty country,
would count ("totalization" in treaty parlance). From what I've been able to determine Japan has social security treaties with the following countries: Germany, the United Kingdom, South Korea, the United States, Belgium, France, Canada (excluding Quebec for some reason), Australia, the Netherlands, the Czech Republic, Spain, Ireland, Brazil, Switzerland, and Hungary. Italy, India, and Luxembourg are going to be added to the list soon (if not already done). If you go to work in any of those countries and contribute into those systems then, assuming non-trivial contributions, you can still hit the minimum vesting period. You could collect pension benefits when the time comes from both Japan and the other treaty country (or countries), depending on your work and contribution history. Check all that, of course, but such considerations properly ought to be part of your financial equation. I'd hate to see you lose about 54% of your gross income
and all the contributions you've made into Japan's social security system if you can avoid it.
Note that it is possible to continue making voluntary contributions into the Japanese national system from overseas. Sometimes that makes financial sense, but it takes a bit of careful study to figure that out. My best guess is that it wouldn't in your situation, that (not to put too fine a point on it) you're screwed if you exit now and don't work in a treaty country (and/or in Japan) in order to hit the minimum vesting period or at least get much closer to it so you can "top up" with voluntary contributions. And the minimum vesting period is scheduled to change, which should help, although that's not a given. (It's tied to the next GST increase, last I heard.)
Another factor I'll toss into your consideration matrix is schooling. If you plan to have any children, Singapore can work -- it's a nice place for kids in many ways (except when the Indonesian fires are burning) -- but schooling is very expensive and/or placement is very difficult here. Japan is quite different that way, and so are other many other countries.
