Change of Self-recognition about the Accuracy of Data on Okinawa in the Mizushima Prefectural Life Table: Influence of His "Pre-publication of the 1921-25 Prefectural Life Table".

We examined the change in the self-recognition about the accuracy of data on Okinawa in the Mizushima Prefectural Life Table, and discussed:its relationship to the "Okinawa Is a Traditional Longevity Prefecture" theory. In the Prefectural Life Table made before WWII, Mizushima had suspended his judgment as to the reliability of infant mortality data in Okinawa. However, after the production of the "Proto-'1921-25' Life Table" in 1952-1954, Mizushima asserted that infant mortality data in Okinawa was incomplete and unreliable, and excluded Okinawa in his analysis in two times of the life table. On the other hand, the "Pre-publication of the 1921-25 Prefectural Life Table" was, in a way that ignores Mizushima's own interpretation, used as the basis of the "Okinawa Is a Traditional Longevity Prefecture" thesis used by the Ryukyu government in its occupation era, and in recent years by other commentators.