Frank Albert Fetter, Capitalization versus Productivity: Rejoinder

Frank Albert Fetter’s journal rejoinder, originally published in 1914 and reproduced in the supplied 1977 version, challenges Harry Gunnison Brown’s defense of the productivity theory of interest. Its central question is whether physical production can supply an independently measurable rate that determines interest, or whether the apparent rate already presupposes valuations governed by time-preference. Fetter proceeds through three connected criticisms: Brown has narrowed productivity’s explanatory claims; his supposedly physical comparisons covertly introduce value relations; and his proposed regulating rate disappears when production methods change. The rejoinder’s significance lies in distinguishing the explanation of productive income from the explanation of the value relationship between that income and its source.

Fetter begins with a qualified concession. Brown has abandoned the attempt to explain interest through producers’ enterprise profits, thereby accepting a more demanding test for productivity theory:

The recent discussion has yielded a substantial result in this admission that the productivity theorist is bound to show the existence of a definite rate of physical productivity to which the rate of interest conforms, quite apart from any borrowing producers' rate of profit.

This concession identifies the argumentative burden rather than announcing agreement. A profit rate cannot establish productivity’s independent explanation if it already incorporates the valuations that interest theory must explain. Brown must instead discover a rate inherent in the physical process itself. Fetter treats this requirement as a useful clarification, but argues that Brown cannot meet it.

The next step exposes the restricted scope of Brown’s revised position. As Fetter presents it, Brown admits that interest could exist under scarcity and desire without physical productivity, and that time-preference operates even where indirect production occurs. Productivity allegedly becomes decisive only under particular circumstances: labor must simultaneously produce fruit through two techniques, a direct method and an indirect method yielding a larger physical output. Fetter regards this narrowing as a substantial retreat. The capitalization theory already explains the cases Brown concedes, while productivity’s remaining claim depends on the coexistence of particular technical alternatives.

The conceptual center of the rejoinder is Fetter’s objection to treating interest as a problem concerning quantities rather than values. Physical output belongs to the explanation of income; interest concerns the valuation of income relative to the asset that yields it:

A theory of interest must be essentially a value-theory. The thing to be explained is the ratio between the value of the income and the value of the income-bearer.

This distinction changes what counts as an explanation. Counting fruit or trees may establish productive capacity, but it does not by itself establish a percentage return. Quantities of different goods cannot be compared as a rate without a common standard of valuation. Brown avoids a money standard, yet, Fetter argues, merely substitutes a present-fruit value standard. The claim that 1,000 present fruit equals 1,100 future fruit cannot express physical equality: the quantities are explicitly unequal. Their equivalence is instead psychological and economic.

Fetter develops the objection through Brown’s tree-and-fruit example. Ten present trees are equated with 1,100 future fruit and, simultaneously, with 1,000 present fruit. The apparent ten-percent productivity rate arises only because both comparisons have already assigned values. It therefore cannot independently explain the valuation of future income against present assets:

Enter the value relation disguised as a rate of physical productivity.

The compact accusation captures Fetter’s criticism of circularity. The physical process supplies fruit, but the claimed percentage surplus depends on valuing the trees or the labor invested in them. Fetter places this maneuver within the persistent cost-of-production fallacy, invoking Böhm-Bawerk as both a critic of its earlier forms and a theorist who subsequently reproduced it. This historical reference serves the polemic: changing the form of the comparison does not remove its dependence on value.

The final substantive section tests Brown’s account against a change in production methods. Suppose the indirect technique offers the alleged ten-percent advantage. If time-preference exceeds ten percent, adopting that technique is uneconomic. If time-preference falls below ten percent, the direct technique becomes uneconomic and is abandoned as rapidly as adjustment permits. Only when time-preference coincides with the supposed productivity rate can both techniques remain equally attractive.

Time-preference dominates the choice among technical methods.

For Fetter, coexistence therefore reflects a valuation condition rather than establishing an autonomous physical regulator. Once all fruit comes from the indirect method, production is more abundant, but the comparison that generated the ten-percent figure no longer operates. An abandoned technique cannot continue fixing current goods prices or time-preference. Greater productivity changes the economic environment without supplying the particular “rate” Brown needs; capitalization must still explain interest under the new conditions.

The conclusion preserves a limited role for the phenomenon Brown describes while rejecting its elevation into a general theory:

This is always but a limited aspect of a dynamic situation (where I have always recognized that it has a place), which in the theory before us is hopelessly confused with the static problem of interest.

Fetter’s point is thus not that technical change is irrelevant. It is that transitional comparisons between methods cannot explain the continuing valuation relationship constitutive of interest. The rejoinder’s core conceptual move separates physical abundance, choice among techniques, and capitalization: productivity can alter available opportunities, while time-preference governs their valuation and remains operative after the technical comparison has disappeared.