The Relationship between Illiteracy Rate and Year of Birth as Seen in Data from the Survey of the Reading and Writing Ability of the Japanese in 1948

Abstract

Using data on illiteracy rate obtained from the survey of the reading and writing ability of the Japanese in 1948, we analyzed the relationship between illiteracy rate and year of birth. Referring to the S-curve theory of language change and the concept of diachronic change analysis using apparent time, logistic regression analysis was conducted with illiteracy rate as the objective variable and year of birth and place of residence (urban or rural) as explanatory variables. The analysis revealed an inverse S-curve relationship between illiteracy rate and year of birth, with the illiteracy rate decreasing with later year of birth (younger age at the time of the survey, with a lower limit of 15 years). The main reason for this is thought to be the increase in the rate of elementary school enrollment over time, which was linked to the introduction of free compulsory education. The analysis also showed that the inverse S-shaped curve of the illiteracy rate in the rural area overlaps with the inverse S-shaped curve in the urban area when the time of six years is shifted parallel to the left along the horizontal axis of the graph (year of birth).