<declan_murphy@hotmail.com> wrote in message

> I was surprised it wasn't a higher figure, and suspect that if the
> period was 5 years it would easily exceed 90%.

I don't think so. A few years ago, my boss had a figure similar to yours for
a 2 year stay and charts saying that :
-the larger % of *giving up Japan* occurs in the 6 first months
-most people first get a short time visa when they arrive (1 year or less).
The majority  don't renew it, or don't even stay in Japan till the end of
the first stint.
-a number of people renew their visa only 1 time, then go away

Then after 2 years, people tend to stay, and even if they leave, they come
back later.

> How many people are
> prepared to risk having every single pension contribution after the 4
> year mark being unfundable?

How many people take the risk of making  *pension contribution* ? 99% of the
gaigins and politicians in Japan have never been concerned by the problem.
And well, that's a backshish among others. In many OECD countries, you
contribute much more and you don't have more chances to get anything back.

Kuri