Population Dynamics in Population Decline Society

In the previous reports [1, 2], we predicted population until 2060 as an initial value with population at 1965. The estimation from in 1970 to in 2000 accorded with investigation value. By which, reliability was provided for a predicted value after 2000. The birth rate in each age grade by the calculation after 2005 was actual birth rate in 2004. In this report, we show effects of birthrate by three scenarios, an optimistic prediction, a pessimistic prediction and a constant prediction as well as last case. The special total birth rate in 2000 was 1.29. We decrease it in a constant ratio in a case of pessimistic scenario-2, and it becomes 0.73 in 2065. The number of the newborn babies becomes a one-sixth. Even in the case of optimistic scenario-1, the number of the newborn babies decreased approximately in half by 2065.