> In Italy, which has more uniform vital registration, remarkable longevity is instead predicted by low per capita incomes and a short life expectancy.
> Finally, the designated ‘blue zones’ of Sardinia, Okinawa, and Ikaria corresponded to regions with low incomes, low literacy, high crime rate and short life expectancy relative to their national average.
For example, it seems that as people get richer their diet becomes less healthy (too much quantity, too much meat, too much processed food, etc).
So there seems to be a sweet spot for healthy diet between "starving poor" and "decadent rich", at least when as long as 'traditional' diets survive.
I was making a general point independent of any fraud or lack of records.
As for the correlations, low incomes would provide a motive for age pension fraud. Short life expectancy being correlated with more supercentenarians suggests it’s not because people in those areas are naturally healthier.
They are specifically pointing out the "blue zones" where a high percentage of supercentenarians live. It's possible that the average literacy of Sardinia is separate from these pockets.
I mean I'm guessing the authors didn't just sit around and say, "hmm, I wonder what the literacy rates are in Sardinia? Let's say low." I guess it's possible though.
For Sardinia they only claim poverty (with a qualitative, non quantitative claim) and life expectancy which, if I'm reading the ISTAT tables correctly, they got spectacularly wrong.
Also there are no blue zones within Sardinia. The demographic data is the for the all the provinces of the island.