Prescription for the 21~st Century Population Problem in Japan

摘要

The rate of birth in advanced countries is decreasing while the aged population grows.In Japan, such tendency is distinctive. The birth number of 2.1 or more per each womanis said to be crucial to sustain the population in one country. This value in Japan is only1.38, and this indicates a necessity of immediate response. We present a Japan-Population-Model to show what happens in the next century. Further, we propose thepolicy set avoiding undesired situations that can be appeared in the future, andintroducing sustainability of a social system in the third millennium.Not only calculating the change of population but also taking an account offeedbacks it was possible to utilize the power of System Dynamics. We included thefollowing feedbacks in the model: labor force, social activities, and welfare. Decreasinglabor population affects economics. Decreasing youth causes lack of social activities.Increasing aged people needs more care. Increasing workingwomen needs supportingsystems such as nursery schools. These feedbacks make rich insights and can alsopresent more effective policy set, the best prescription. As a result the model has animportant social impact in Japan.