Extended Harrod = Domar models

The purpose of this paper is to present some extended models of Harrod=Domar model and explain the stagnation of Japanise economy. Neoclassical growth model has big problems, so Harrod=Domar model is better than that.But Harrod=domar model has some ploblems. Considering the problems. Considering the problem, I made some extended models. Using the third extended model, we can explain the stagnation of japanese economy.