I have insisted that econometrics must have relevance to concrete realities, otherwise it degenerates into something which is not worthy of the name … - Ragnar Frisch

There is also present another source of energy operating in a more continuous fashion and being more intimately connected with the permanent evolution in human societies.

In this essay on econometrics in its conception and its use in economic planning for the betterment of man’s fate, I will try to cover a very broad field. When talking about the methodology in the particular fields mentioned - about which I am supposed to have a little more than second hand knowledge - I have always found it utterly inadequate to focus attention only on these special fields without seeing them in a much broader perspective. Therefore it was inevitable that I should have to include in the field of vision of this paper also some branches of science where I can only speak as a layman, hopefully as a somewhat informed layman. For whatever blunders I may have made in these fields I must ask for the reader’s forgiveness

The majority of the economic oscillations which we encounter seem to be explained most plausibly as free oscillations.