G. L. S. Shackle, “‘Expectation in Economics’: Some Critics Answered”

This short note, first published in 1949, is Shackle’s reply to critics of Expectation in Economics. It defends his view that many economic decisions cannot be understood through the probability calculus appropriate to repeatable trials. Shackle’s target is not calculation as such, but the assumption that a chooser facing a singular future can treat rival imagined outcomes as additive elements in one statistical expectation.

Shackle distinguishes unique, isolated, and crucial trials, giving priority to the last because it alters the very conditions under which any later choice would occur.

The most fundamental and essential source of uniqueness in a trial is crucialness (see below).

A crucial decision is not like drawing again from the same urn. It is more like a move in a game whose consequences reshape the board. Economic action, on this view, is temporally creative: by choosing, the individual enters a future partly made by the choice itself.

By a crucial trial I mean one whose outcome, like a chess-move, will affect the whole future course of relevant events for the individual.

This claim grounds Shackle’s rejection of expected-value reasoning in cases of genuine uncertainty. If the alternatives are mutually exclusive imagined futures, they cannot be added together as if each contributed a measurable fraction to a common total. The chooser does not possess a population of comparable trials; he has an act, a moment, and a set of rival hypotheses about what that act may bring.

Now when an experiment, a question about the future, is unique, isolated, or crucial, it does not make sense to add together its rival hypothetical outcomes or answers.

From this follows the role of Shackle’s characteristic concepts: focus-values, focus-gain, focus-loss, and potential surprise. Uncertainty is not a blurred average of possibilities but the coexistence of separately entertained hypotheses, each carrying a different imaginative force. A disastrous outcome that is not surprising cannot be neutralized merely because other pleasant outcomes are also conceivable. Likewise, the presence of several favourable hypotheses does not dilute the mind’s exposure to one fully possible loss.

Shackle therefore reads choice as an imaginative act. The individual must select some outcome or pair of outcomes as decisively relevant to the comparison of alternatives. This is not arbitrary fantasy but a way of representing the fact that future satisfactions can affect present choice only through present anticipation.

To decide between rival courses of action when each is a crucial or unique experiment, a man must surely choose for each some single clear-cut hypothesis to give him that enjoyment by imagination which is all the good that something in the future can give him.

The note also answers technical objections, especially those concerning whether Shackle’s system can handle simple gambles such as a certain £1 against a coin toss yielding £1 or nothing. He considers whether his $\phi$-function needs an additional variable connected with belief in the contradictory of a hypothesis, but rejects this as unnecessary. For him, “degree of belief” cannot generally restore probabilistic ordering where the problem is precisely the non-repeatable and crucial character of the act.

The essay’s importance lies in its compact defense of Shackle’s larger project: replacing expectation as probabilistic averaging with expectation as disciplined imagination under uncertainty. It insists that economic decision is often not a calculation over known frequencies but a confrontation with possible futures whose plausibility, vividness, and power to attract or repel cannot be reduced to additive probability.