The Demographics of Defense and Security in Japan

Abstract

Long-term demographic trends influence defense and security policies and international politics in multiple ways. This paper forecasts the size and the age and sex composition of the Japanese population until 2080 and estimates its impact on the recruitment pool of military forces. We use a stochastic population forecasting method based on coherent functional data models for mortality, fertility and migration. Our results show that the country will experience a prolonged period of total and working-age population decline and ageing, with major negative implications on the recruitment and retention of SDF forces. Potential remedies to uphold the country's security and defense capabilities are discussed. Our approach can be extended to other demographic markers and to other countries and inform public and private decision making.