Population, Birth and Death in Japan for the Period 1890-1920

Abstract

Japanese mortality statistics since 1872 shows upward trend in overall mortality until 1920, and thereafter mortality goes down. Whether this was true or just an artifact caused by improvement in death registration rate has been a matter of debate. The author tried to examine the accuracy and completeness of death registration data for the period 1890-1920. Death registration data by single year of age were adjusted for lay reporting (1.5%) and emigration (3.5%) and then re-arranged as cohort decrement data by year of birth. The first census population (Oct. 1, 1920) by single year of age was also re-arranged as cohort data and by adding up the cohort decrement data, year by year, the population was moved back to the beginning of 1890. Estimated series of annual birth and age-specific population for the period 1890-1919 were compared with the series of registered birth and the Honseki population (registered population), which was believed to be highly reliable around 1890. The result showed striking coincidence between either the two series of annual birth or the age-specific populations estimated and registered at the beginning of 1890. But this was not the case with the other published estimates, which were derived from the same base population but making use of the estimated life tables, that imply increasing mortality toward 1890. Although, there are some evidence to believe that the registration rate of infant deaths have increased on a large scale soon after the promulgation of "The Graveyard and Burial Regulation Law" in 1984, which provided the necessity of reporting death and stillbirth, in order to get "Burial Permit", there are no reasons to suspect the trend of the recorded mortality. Because, the procedure of death reporting have not been changed thereafter, and the neonatal mortality rate, which is most likely to be affected by under-reporting, continues to decline since 1900, while the post-neonatal mortality continues to rise. After all, registered mortality data for the period 1890-1920 are believed to be highly reliable and would be a valuable source of data for the study of the early stage of mortality transition.