The Nature of the Firm
By R. H. COASE
ECONOMIC theory has suffered in the past from a failure to state clearly its assumptions. Economists in building up a theory have often omitted to examine the foundations on which it was erected. This examination is, however, essential not only to prevent the misunderstanding and needless controversy which arise from a lack of knowledge of the assumptions on which a theory is based, but also because of the extreme importance for economics of good judgment in choosing between rival sets of assumptions. For instance, it is suggested that the use of the word “ firm ” in economics may be different from the use of the term by the “plain man.”l Since there is apparently a trend in economic theory towards starting analysis with the individual firm and not with the industry,2 it is all the more necessary not only that a clear definition of the word “firm ” should be given but that its difference from a firm in the “ real world,” if it exists, should be made clear. Mrs. Robinson has said that “ t h e two questions to be asked of a set of assumptions in economics a r e : Are they tractable ? and : Do they correspond with the real world ? ”3 Though, as Mrs. Robinson points out, “ more often one set will be manageable and the other realistic,” yet there may well be branches of theory where assumptions may be both manageable and realistic. It is hoped to show in the following paper that a definition of a firm may be obtained which is not only realistic in that it corresponds to what is meant by a firm in the real world, but is tractable by two of the most powerful instruments of economic analysis developed by Marshall, the idea of the margin and that of substitution, together giving the idea of substitution a t 1
Joan Robinson, I~corro~rrzcs a Serious Subjecr, p. 12. as See N. Kaldor, “ T h e Equilibriuin of the Finn,” h c o m m z c J o u r m l , March, 1934 Op. cit., p. 6.
T H E NATURE O F T H E FIRM
the margin.’ Our definition must, of course, “relate t o formal relations which are capable of being conceived exactly.”2
It is convenient if, in searching for a definition of a firm, we first consider the economic system as it is normally treated by the economist. Let us consider the description of the economic system given by Sir Arthur Salter.3 “ The normal economic system works itself. For its current operation it is under no central control, it needs no central survey. Over the whole range of human activity and human need, supply is adjusted to demand, and production t o consumption, by a process that is automatic, elastic and responsive.” An economist thinks of the economic system as being co-ordinated by the price mechanism and society becomes not an organisation but an organism.4 The economic system “works itself.” This does not mean that there is no planning by individuals. These exercise foresight and choose between alternatives. This is necessarily so if there is t o be order in the system. But this theory assumes that the direction of resources is dependent directly on the price mechanism. Indeed, it is often considered to be an objection to economic planning that it merely tries to do what is already done by the price m e ~ h a n i s m . ~ Arthur Salter’s Sir description, however, gives a very incomplete picture of our economic system. Within a firm, the description does not fit at all. For instance, in economic theory we find that the allocation of factors of production between different uses is determined by the price mechanism. The price of factor A becomes higher in X than in Y . As a result, A moves from Y to X until the difference between the prices in X and Y , except in so far as it compensates for other differential advantages, disappears. Yet in the real world, we find that there are many areas where this does not apply. If a workman moves from department Y to department X,he does not go because of a change in...