As a general principle of economics it is said that growth is a function of investment. But to sustain growth it is not enough that a country has a high investment rate only. It is also needed that investment has to be A B C D exactly the same year after year and at least for a period of five years. rising year after year and that too for many years. decrease after a period of two/three years. withdrawn after a period of three years so that the growth can be spread uniformly.