SEMAINE D'ÉTUDE SUR LE ROLE DE L ANALYSE ECONOMETRIQUE ETC.

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no longer with a problem of rationality, but with a process of
learning. Any mathematical formulation of it cannot but be
in terms of functions of time, since the process makes short
steps, and may appear quite negligible, in the short run; but,
as it goes on incessantly, it is inevitably bound to become the
more pronounced the longer the period which is considered.
The contrast with the simple concept of trade is now evident.
The passage from a position of no trade to a position of trade
means a jump, which may be quite big but which is temporary,
 as it ends when the new equilibrium situation has been
reached. The process of learning associated with industry, on
the other hand, means a persistent movement, not a once-for-all
change, but a rate of change in time — a movement which is
cumulative and indefinite. In this sense, industry comes to
realise most properly the concept of progress which is inherent
in modern society.
Clearly, these are two distinct series of problems. A particularly
 important difference between the two, for theoretical
analysis, is that they acquire an opposite practical relevance
in relation to time, the former being relevant (in the short run)
just when the latter is practically irrelevant and the latter becoming
 relevant just when (in the long run) the former becomes
irrelevant. Both series of problems have been of course considered,
 in the course of development of economic thought. But
according as to whether the economic theorists have been
mainly impressed by the former or by the latter, the attitude
they have taken to the type of hypotheses to choose has been
diametrically opposite.

2. Scarcity versus learning tn economic analysis

There are clear indications — it seems to me — that the
Classical economists, writing under the strong impact of the
English « industrial revolution », were well aware of the two

-10] Pasinetii - pag. 5