> Japan is such a high trust society I would be shocked if this is the reason
Trust works both ways. There's also the trust that nobody will report anyone for the fraud, especially if it is widespread and normalized.
However, it would not surprise me if Japan actually did have high life expectancy rates because several other statistics seem to correlate with that, including low obesity, and universal access to healthcare.
I don't remember the source, but worldwide, most really old people have a couple things in common. First is that they live in countries with some kind of pension plan. Second, they generally come from poor neighborhoods where all the people around them statistically have lower lifespans.
