This book consists of two sections that discuss the micro economics and macro economics. The main purpose of the present revision is to take more adequate account of the theory of savings and investment and to give the beginner at least a cursory view of the field of macro-economics. Whether we agree fully with the Keynesian theory or not, and regardless of whether we accept the practical measures to meet the problem of unemployment that are offered by Keynes and Hansen and their followers, we cannot afford to ignore the impact upon traditional economic theory which has been made by the theory of savings and investment. In order to make it more understandable, the subject is treated in terms of planned saving and planned investment rather than in the more elegant.i