Econometrics is by no means the same as economic statistics. Nor is it identical with what we call general economic theory, although a considerable p… - Ragnar Frisch

Usually it is easier to obtain estimates for budget proportions and Engel elasticities than for elasticities with respect to price. By making certain want independence assumptions, the elasticities with respect to price can be deduced from the knowledge of budget proportions and Engel elasticities. In this connection the concept of the flexibility of the marginal utility of money is essential. A system of formulae decribing these relations is given.

[The] length of the cycles and the tendency towards dampening are determined by the intrinsic structure of the swinging system, while the intensity (the amplitude) of the fluctuations is determined primarily by the exterior impulse. An important consequence of this is that a more or less regular fluctuation may be be produced by a cause which operates irregularly.

We may perhaps start by throwing all kinds of production into one variable, all consumption into another, and so on, imagining that the notions 'production', 'consumption', and so on, can be measured by some sort of total indices. At present certain examples of micro-dynamic analyses have been worked out, but as far as I know no determinate macro-dynamic analysis is yet to be found in the literature.