Paul Narcyz Rosenstein-Rodan, Grenznutzen (1927)

Rosenstein-Rodan’s signed encyclopedia entry presents marginal utility as the organizing principle of economic calculation under scarcity. Its three divisions establish the foundations of calculation, explain marginal utility’s operation in consumption, production, and exchange, and survey the theory’s literature and critics. An extensive international bibliography completes the contribution. The entry combines systematic exposition with a forceful defense of modern economic theory, while rejecting several familiar mathematical formulations of marginalism.

The foundations begin with anticipated needs rather than immediately experienced pleasures. Economic agents draw on experience to arrange needs across a planning period, distinguishing their psychological intensity from their considered importance for welfare. Utility arises when the importance attributed to a need is transferred to a good capable of satisfying it. Consequently, expected utility, not satisfaction subsequently realized, explains the decision. Welfare is defined formally: altruistic, ethical, and imagined ends belong within the analysis alongside other purposes.

The overarching concept is Gesamtwirtschaftsnutzen, the individual’s welfare considered as a whole. Particular utilities express changes in that welfare, but practical calculation need not repeatedly estimate the whole. Rosenstein-Rodan distinguishes directly dependent utility, assessed while other uses remain unchanged, from indirectly dependent utility, assessed after an appropriate reallocation of the remaining goods. The latter is marginal utility: substitution reduces the loss attributable to any particular unit.

Eine Messung der Nutzen ist weder nötig noch möglich.

English translation: Measurement of utilities is neither necessary nor possible.

This rejection of measurement does not preclude comparison. Decisions require judgments that one utility is greater than, equal to, or smaller than another; they do not require homogeneous utility units. Rosenstein-Rodan also permits comparisons between utility differences without numerical measurement. His position therefore should not be reduced without qualification to a strictly ordinal account. Nevertheless, it excludes utility ratios and division of utility by an objective price quantity.

Complementarity makes allocation a problem of the entire configuration of needs and goods. A good’s utility depends on other holdings and their uses, not merely on its own supply. Psychological complementarity must be distinguished from the technical necessity of combining inputs. Consumption and production plans must therefore be reconstructed as coordinated selections among feasible combinations. Time also belongs among their determining conditions: recurrent needs must be ranked across a defined economic period, whose limits depend on production requirements and the agent’s foresight. Diminishing utility applies within a particular episode of need; planning across recurring episodes produces descending layers that may contain equal utilities.

The entry’s central move explains how this interdependent system remains practically manageable. Marginal utilities emerge from an allocation already formed through experience, yet subsequently guide its alteration.

Ihre Funktion besteht also darin, daß sie durch die unmittelbare Anknüpfung an die bisherige wirtschaftliche Situation und an ihre Grenzergebnisse die ungeheure Aufgabe, bei jeder wirtschaftlich relevanten Veränderung den Aufbau der Gesamtdisposition immer von neuem in Angriff nehmen zu müssen, ersparen.

English translation: Their function thus consists in sparing the enormous task of having to undertake the construction of the overall allocation anew with every economically relevant change, by connecting directly to the previous economic situation and its marginal results.

Marginal utility is thus an instrument of abbreviated calculation, not an unexplained starting point. Most important needs and productive capacities remain relatively stable between periods; changes ordinarily affect lower-ranked uses, where complementarity is comparatively loose. Under these conditions, selected marginal comparisons yield an exactly appropriate adjustment, not merely an approximation. The qualification matters: the shortcut rests on substantive psychological and technical regularities. Experience preserves these results, but cannot serve as their ultimate explanation without circularity.

Production extends the same argument. Productive goods derive utility from their products, while costs register the utility sacrificed in alternative uses. Wieser’s cost law allows reproducible consumer goods to be valued through the marginal product displaced by replacement. Even the burden of labor can enter the unified ranking as the utility of forgone leisure. Economic marginal productivity is accordingly identified with the marginal utility of productive resources.

Rosenstein-Rodan nevertheless resists the conventional equalization of marginal utilities. Discontinuous needs and imperfectly divisible goods invalidate its general empirical claim.

Der Zustand, bei dem keine Verfügungsänderung eine Erhöhung des Gesamtwirtschaftsnutzens eines Wirtschafters noch bringen könnte, ergibt für ihn seinen Gleichgewichtszustand.

English translation: The state in which no change in allocation could bring any further increase in an economic agent’s overall economic utility constitutes that agent’s equilibrium state.

Equilibrium therefore means the absence of a welfare-improving reallocation, not a universally equal marginal level. Exchange likewise requires a more careful comparison than two marginal utilities: Rosenstein-Rodan compares the indirectly dependent utility of the good acquired with the directly dependent utility of the good surrendered. Prices make qualitative valuations quantitatively effective through maximum bids and purchasing power, rather than by measuring utility or reproducing utility ratios.

The final division locates Austrian process-oriented explanation and Lausanne equilibrium analysis within a common marginal-utility framework. Thirteen categories of objections receive largely rebuttal-oriented treatment. Methodological individualism does not imply selfishness or political liberalism; social and legal conditions enter through needs, holdings, and powers of disposal. Historically inherited allocations remain essential even to general theory. Rosenstein-Rodan rejects collective utility as the experience of a societal subject and separates normative welfare judgments from pure theory. The entry’s relevance lies in this distinctive synthesis: marginalism becomes a theory of historically continuous, interdependent choice whose practical operation depends on selective calculation, while complementarity, unmeasurability, and time qualify its simpler textbook formulations.