¹ However Proudhon distinguishes, whith exceptional lucidity, "institutional contradictions which lead to distruction," and "antinomy" a functional "contra diction" that "results in movement" and "aims at production." Cf. new edition Œuvres choisies (Gallimard, Collection "Idées").

² Pareto, like Walras, an engineer, is also the author of a thesis on "The equilibrium of physical bodies."

³ Cf. H. Guitton, Fluctuations et croissance économiques (Dalloz).

⁴ Di Nardi, "Dynamic Interdependence and Irresoluteness in the Theory of Economics", published in Padua in 1941 and again in "Economie et Société," (Cahiers de l'I.S.E.A., No. 2, 1967).

⁵ "Une théorie de l'économie dominante," Cahiers de l'I.S.E.A., April-Septem ber, 1948; "Note sur les pôles de croissance," Economie appliquée, June 1951.

⁶ Antagonisticheskie i neantagonisticheskie protivorechiaa (Moscow 1954).

⁷ Traité d'économie politique (1959).

⁸ The Strategy of Economic Development, (1958).

⁹ These sentences are taken from texts written between 1948 and 1951 and reproduced in the great economist's fundamental work: L'économie du XX^e siècle (Presses Universitaires de France), cf. pp. 169, 553, 257, 250 and 263.

¹⁰ Paul Streeten in his "Unbalanced Growth" (Oxford Economic Papers, June 1959) puts forward similar ideas simultaneously with Hirschman. His name should therefore be added to the list of the economists I am examining.

¹¹ "L'économie généralisée et la pensée actuelle d'Oskar Lange" by A. Nowicki (Cahiers de l'I.S.E.A., June 1961, Series G.).

¹² In his book Stages in Economic Growth.

¹³ The formulation of these criteria and the analysis that follows are my own, but they are a faithful interpretation of Hirschman's development.

¹⁴ The theory of Responsibility of an Economy that I develop in this article (cf. pp. 99, 102, 103, 110 and 111) is my own, but I consider it to be the corollary of any theory of unbalanced growth.

¹⁵ On the difficulty of fulfilling these two roles cf. my article on "Les limites d'une économie concertée" (Perspectives, 18 February, 1961).

¹⁶ I must stress that both Hirschman and O. Lange have kept up an open dialogue with the author of L'économie du XX^e siècle and that Hirschman also refers to Kozlovskii in The Strategy of Development.

¹⁷ "Une philosophie de l'action: Les idées-maîtresses de F. Perroux" (Entreprise, 10 November 1966).

¹⁸ On this point see my article "Les investissements étrangers et le danger des usines flottantes" (Perspectives, 14 January 1961).

¹⁹ Cf. pp. 95, 102, 103, 110 and 111 in this article.

²⁰ This expression is preferable to "harmonized growth," also used by F. Per roux, which allows certain uninformed people to believe that the author of L'économie du XX^e siècle was a partizan of balanced growth, a most unfortunate misinterpretation.

²¹ Cf. pp. 95, 99, 103, 110 and 111 in this article.

²² Cf. pp. 95, 99, 102, 110 and 111 in this article.

²³ Cf. on this point my articles "Vers une planification incitative" (Perspectives, 11 March 1961) and "Espoirs et difficultés de la planification" (Jeune Patron, No. 152, April 1962).

²⁴ By grappling with the notion of tolerable disequilibriums, as early as 1948, F. Perroux, together with James Knowles, has made an essential contribution to the elaboration of a scientific theory of unbalanced growth. By clarifying, with Hirschman, the notion of equilibrium, he also indicated the practical limits of the generating role of disequilibriums. While emphasizing the "imaginary" character of classic economic equilibrium, he warned against the "doctrinaire" character of certain modern theories that tend to present economic disequilibriums as mechanisms for generating growth automatically.

²⁵ By taking into account these power relations and their variations in time and space, the economist is able to compare similar socio-economic disequilibriums usefully, and to measure tolerable economic disequilibriums scientifically. By not taking these into account, disequilibriums that bear no relation one to another are often compared. F. Perroux ("Les trois analyses de l'évolution… chez Schumpeter," Economie appliquée, No. 2, 1951) condemns the naïvety, whether conscious or unconscious, of comparing, with economic action in mind, the socio-economic equilibriums of countries and epocs with different social organizations. In The Statics of Development, Hirschman also warns against this error.

²⁶ Cf. on this subject my article on "La socio-économie de Proudhon" (Cahiers de l'I.S.E.A., April 1966).

²⁷ Cf. L'économie du XX^e siècle, p. 226. All quotations in this article without references are taken from this fundamental work.

²⁸ In order to apprehend objectively a lasting economic disequilibrium, be it tolerable or intolerable, one must measure the three factors that interpret it. These factors are none other than (a) "the inequality of fluxes" or rather the relation between the movements of at least two different economic dimensions; (b) "per sisting inequality" (the momentary inequality of fluxes is merely a normal charac teristic of economic movement); (c) finally a social and political comprehension of this persisting inequality (or rather its apprehension on a level of pratical economic policy).

Once economic disequilibrium has been objectively evaluated in this way one must then measure the degree to which it can be tolerated. To do so one must first try to measure, sociometrically, the "power relations between social groups." So as to appreciate the power of different social groups one must take into account three essential factors: (a) "the capacity for self-assertion of the social groups" (which depends on their number, their concentration, their degree or organization, their strategy and their ability to exert pressure on public authorities and public opinion); (b) their "capacity for resistence" when their standards of living are lowered or when the slightest relative increase in population occurs (this capacity for resistence does not necessarily coincide with their capacity for self-assertion); (c) lastly to complete the measuring of the degree to which disequilibriums can be tolerated, one should compare these two determining factors: the social plasticity of economic agents and the technical plasticity of the economic ap paratus (cfr. "Les trois analyses," quoted in note 25).

One should note that these social groups and their power relations continue to exist whatever the economic system adopted. Thus the Pole Oskar Lange distin guishes, within a socialist economy, "social strata" with opposing interests.

²⁹ This analysis of tolerable disequilibriums and their measurement should be compared with the theory of the "zone of acceptable variation" that James W. Knowles expounded some ten years later in The Potential Economic Growth of the United States (Washington, 1960). This economist studies the possibility of establishing a stable relation between production capacity (the "physical limits of growth") and production potential (the "economic limits of growth"), and defines the latter as the "optimal activation that an economy is believed to be able to bear in an average year, without suffering from serious instability in employment, pro duction and prices."

Later the concept of potential production was perfected as a statistical instru ment by the Committee of economic Counsellors to the President of the United States, to help the President to exercise his economic responsibilities. Starting from a report on the real P.N.B. correlative of employment and establishing an employment target of a 4 % rate of unemployment of the active population, they calculated a potential P.N.B. This last aims at interpreting the potential economic rate of growth (by supposing that the rate of use of the labour resources will vary parallel to the rate of the use of capital, and that an unemployment of 4 % of the active population is a tolerable social disequilibrium).

Very close to this, though not so global and more pluralistic, is the system per fected by the French V^e Plan. As B. Cazes points out (La vie économique, A. Colin, 1965), the rate of growth of the Plan corresponds to a production potential that has to be achieved, and the zone of acceptable variations is in fact restricted by the 5 indicators of the Plan.

Two remarks should be made about these two systems, American and French, whose relationshinp to F. Perroux's earlier model is undeniable. First the limits to disequilibrium are based on an experimental process whose statistical basis inclu des, by reference to the past, rather rough and ready social hypotheses (for instance an acceptable unemployment rate). Secondly the calculation of the po tential American P.N.B. allows an unemployment of 4 % of the active popula tion as acceptable, whereas in the same case the French V^e Plan limits this unemployment to 2,5 % of the active population. This sythesizes the whole social contingency of the measuring of acceptable disequilibriums.

³⁰ A. Agnati "… Modèles, analogies et théories." "Economie et societé" (Cahiers de l'I.S.E.A., January 1967).

³¹ "Economic progress is the opposite of a prefabricated building" (F. Perroux). Its duration, its concrete objectives, its terms, its cumulative effects, should all be discovered through social experimentation. Tolerable disequilibriums, Hirschman's optimal disorder, discovered after a procedure of collective groping, will be meas ured by exploratory models of a probabilistic nature. These voluntaristic models are made up of the calculation of multiple errors and variants of the policies of growth, together with their specific rates of development and the proportion of unproductive disequilibriums they contain. ("Sur la science économique," Revue de l'enseignement supérieur, No. 2, 1960).

³² Hirschman expresses an identical opinion.

³³ A strategy of harmonized growth tries: to increase the trend (by increasing the volume of the resources that are used and by a better combination of these resources thanks to innovation and its distribution in the economic area), to attenuate fluctuations (thanks to the use of automatic stabilizers, monetary and fiscal policies, selective actions to reduce non-productive disequilibriums between sectors) and the reduction of intolerable tensions between agents (thanks to a redistribution of revenues, and an active system of information and participation in the objectives of growth).

³⁴ Cf. my article "L'ère des comptabilités nationales" (Le monde, 15, 16 and 17 September 1965).

³⁵ Les projections à court terme des comptes nationaux (forthcoming in the Presses Universitaires de France. Collection: Bibliothèque de l'Economie Contem poraine, étude I.S.E.A.).

³⁶ Cf. pp. 95, 99, 102, 103 and 110 in this article.

³⁷ Pope Paul's Encyclical "on the development of nations:" "Development must promote all of man and the whole of mankind."