2014 Volume 80 Issue 1 Pages 6-11
The latest population projection for Japan showed that during the next 50 years, the dependency ratio will drastically increase from 0.58 (2010) to 0.94 (2060) and that the population will decrease from 128 million (2010) to 87 million (2060). There is concern that burdens placed upon the working-age population will increase and that the social security system of the nation might eventually collapse. We report here the results of population projections under four scenarios of changes in vital statistics rates that reflect the current demographic policies in Japan. These four scenarios assume that specific vital statistics rates change as follows. Scenario 1 : The total fertility rate will increase to 2.1 (replacement level) in 2010. Scenario 2 : The in-migration rate at 18 years of age will increase to 0.1. Scenario 3 : The start of old age is redefined as 70 years. Scenario 4 : Age-specific mortality at age 65 years or older will double. Scenarios 1 and 2 mitigate the population decrease, but Scenario 1 increases the dependency ratio for the initial 40 years. Scenario 3 drastically decreases the dependency ratio without affecting the population size or structure. Scenario 4 suppresses the increase in the dependency ratio, but decreases the population size. If all four scenarios occurred simultaneously, the dependency ratio in 2060 would remain at the level observed in 2005.