ABSTRACT
We have already stated that econometric investigations should be started by setting up one or more relations between the magnitudes to be studied, with the help of mathematical-economic methods. When this has been done–we have called it the first stage of the investigation–the statistician has the floor. He will try to ascertain whether the supposed relations agree with the facts and if so, whether the measuring of certain magnitudes will make it possible to obtain more concrete information concerning those relations.
