I believe that economic theory has arrived at a point in its development where the appeal to quantitative empirical data has become more necessary th… - Ragnar Frisch

In the last decade's intensive study of all sorts of social and economic time series, it has become clear, it seems to me, that the usual time series technique is not quite adequate for the purpose which the social investigator is pursuing... We want to find out on more or less empirical grounds what is actually present in the series at hand, that is to say, what sort of components the series contains.

To proceed from assumptions about an abstract theoretical set-up and from them to draw conclusions about the observable world and to test - by rough or more refined means - whether the conformity with observations is "good" enough, is indeed the time honoured procedure that all empirical sciences, including the natural sciences, have used. I shall therefore not plead guilty of heresy even if I do work with choice-theory concepts that are not invariant under a general monotonic transformation of the utility indicator.

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