中世纪商业中的声誉与联盟英文版

Economic History Association Reputation and Coalitions in Medieval Trade: Evidence on the Maghribi Traders Author(s): Avner Greif Source: The Journal of Economic History, Vol. 49, No. 4 (Dec., 1989), pp. 857-882 Published by: Cambridge University Press on behalf of the Economic History Association Stable URL: http://www.jstor.org/stable/2122741 Accessed: 23/12/2008 00:46 Your use of the JSTOR archive indicates your acceptance of JSTOR's Terms and Conditions of Use, available at http://www.jstor.org/page/info/about/policies/terms.jsp. JSTOR's Terms and Conditions of Use provides, in part, that unless you have obtained prior permission, you may not download an entire issue of a journal or multiple copies of articles, and you may use content in the JSTOR archive only for your personal, non-commercial use. Please contact the publisher regarding any further use of this work. Publisher contact information may be obtained at http://www.jstor.org/action/showPublisher?publisherCode=cup. Each copy of any part of a JSTOR transmission must contain the same copyright notice that appears on the screen or printed page of such transmission. JSTOR is a not-for-profit organization founded in 1995 to build trusted digital archives for scholarship. We work with the scholarly community to preserve their work and the materials they rely upon, and to build a common research platform that promotes the discovery and use of these resources. For more information about JSTOR, please contact support@jstor.org. Economic History Association and Cambridge University Press are collaborating with JSTOR to digitize, preserve and extend access to The Journal of Economic History. http://www.jstor.org Reputation and Coalitions in Medieval Trade: Evidence on the Maghribi Traders AVNER GREIF This article examines the economic institution utilized during the eleventh century to facilitate complex trade characterized by asymmetric information and limited legal contract enforceability. The geniza documents are employed to present the "coalition," an economic institution based upon a reputation mechanism utilized by Mediterranean traders to confront the organizational problem associated with the exchange relations between merchants and their overseas agents. The theoretical framework explains many trade-related phenomena, especially why traders utilized specific forms of business association, and indicates the interre- lations between social and economic institutions. M editerranean trade contributed much to the economic growth of southern Europe during the Middle Ages.' The spread of this trade depended, to a large extent, upon traders' ability to employ overseas agents or to let business associates function as overseas agents. The employment of overseas agents was vital during the Middle Ages, since goods were sold abroad only after being shipped to their destination.2 Since, absent contractual problems, a merchant can de- crease cost by sending goods to an overseas agent rather than traveling with his goods, a large efficiency gain could potentially be achieved by employing overseas agents.3 The Journal of Economic History, Vol. XLIX, No. 4 (Dec. 1989). C The Economic History Association. All rights reserved. ISSN 0022-0507. The author is Assistant Professor of Economics at Stanford University, Stanford, CA 94305. The article was written while the author was at Northwestern University. I am grateful to J. Mokyr, J. Panzar, and W. Rogerson for helpful discussions and encouragement. The detailed remarks of an anonymous referee and the editor enriched this work. I received many stimulating comments from participants at seminars held at Northwestern University, the University of Chicago, the University of Texas at Austin, Stanford University, M.I.T, Yale, the University of Arizona at Tucson, the University of Michigan at Ann Arbor, and Washington University in St. Louis. The research was supported by the Sloan Dissertation Fellowship. The usual caveat applies. 1 R. S. Lopez, "The Trade of Medieval Europe in the South," in M. M. Postan and E. Miller, eds., The Cambridge Economic History of Europe (New York, 1952), vol. 2; R. S. Lopez, The Commercial Revolution of the Middle Ages, 950-1350 (New York, 1976). H. Pirenne, Mohammed and Charlemagne (New York, 1939); H. Pirenne, A History of Europe (New York, 1956). 2 R. de Roover, "The Organization of Trade," in M. M. Postan, E. E. Rich, and E. Miller, eds., The Cambridge Economic History of Europe (Cambridge, 1963), vol. 3, p. 44; S. B. Gras, Business and Capitalism, An Introduction to Business History (New York, 1939); G. Porter, and H. C. Livesay, Merchants and Manufacturers (Baltimore, 1971). 3 The superiority of trading systems that employ agents over those that do not has been shown by many scholars. See, for example, de Roover, "The Organization of Trade," pp. 43, 45 ff., 70 ff.; M. M. Postan, Medieval Trade and Finance (Cambridge, 1973), pp. 66 ff.; R. S. Lopez, and I. W. Raymond, Medieval Trade in the Mediterranean World (New York, 1955), p. 174. 857 858 Greif C. M. Cipolla has pointed out that the contractual problems associ- ated with agency relations could be resolved neither by the legal system nor by the anonymous market. These problems arose from the fact that the agent who traded using someone else's capital "could easily have disappeared with the capital or cheated in business conducted in far-off markets where none of his associates had any control."4 The traders faced an organizational problem: cooperation leads to efficiency gains that the anonymous market for agents' services fails to capture. Until recently economic theory provided no framework within which such contractual problems could be investigated. Some scholars, such as R. S. Lopez and R. de Roover, have restricted their investigations of trade organization to forms of business association, implicitly assuming that the legal system was able to supervise and enforce the execution of all contracts. Other scholars have examined the establishment of "trust" relations among traders, focusing in particular on the role of social control systems and ethics. W. Sombart pointed out the impor- tance of relationships within "natural groups," such as clans and tribes. N. Rosenberg and L. E. Birdzell Jr. emphasize loyalty relationships within a specific natural group-the family-and argue that "apart from the family, the Middle Ages offered no satisfactory model for mercantile enterprise." Following Max Weber, many scholars have stressed the role of ethics in surmounting contractual problems, emphasizing either implicitly or explicitly altruism ("taking pleasure in others' pleasure"), impure altruism (internalized norms of behavior), and fear of God.5 This article examines the economic institution that enabled eleventh- century Mediterranean merchants to deal with the contractual problems that arose from the fact that neither a merchant nor the judges possessed all the information available to "overseas agents," individuals who provided trade-related services to geographically remote merchants. The evidence suggests that the observed "trust" reflects a reputation mechanism among economic self-interested individuals.6 By establish- ing ex ante a linkage between past conduct and a future utility stream, an agent could acquire a reputation as honest, that is, he could credibly I C. M. Cipolla, Before the Industrial Revolution (2nd edn., New York, 1980), p. 198. 5 Lopez, The Commercial Revolution; de Roover, "The Organization of Trade"; W. Sombart, "Medieval and Modern Commercial Enterprise," in F. C. Lane and J. C. Riemersa, eds., Enterprise and Secular Change (Homewood, 1953); N. Rosenberg and L. E. Birdzell, Jr., How the West Grew Rich (New York, 1986); M. Weber, General Economic History, trans. by F. H. Knight (New York, 1927). 6 By self-interested individuals I refer to individuals whose utility function is defined over their effort and money income. On the old debate between sociologists and economists concerning the rational versus the social man, see H. A. Simon, Models of Man, Social and Rational (New York, 1987) and J. T. Landa, "A Theory of the Ethnically Homogeneous Middleman Group: Beyond Markets and Hierarchies," working paper, The Hoover Institution, Stanford University, 1988, p. 14. For a discussion of cooperation versus free riding, see R. M. Dawes and R. H. Thaler, "Anomalies: Cooperation," Journal of Economic Perspectives, 2 (Summer 1988), pp. 187-97. Maghribi Traders 859 commit himself ex ante not to breach a contract ex post.7 To examine the institution through which agency relations were organized is to study how this linkage was created and the-contractual arrangements aimed at facilitating the operation of the reputation mechanism.8 The evidence indicates that an economic institution, and not social control systems or ethics, played an important role in generating this linkage. The evidence indicates that eleventh-century Mediterranean traders arranged agency relations through a peer organization that may be referred to as a coalition. Members of the coalition provided each other with agency services that increased the value of a member's capital. Each trader benefited from being a coalition member more than he could have by establishing agency relations based upon a reputation mecha- nism outside the coalition. Obtaining the benefits of coalition member- ship depended upon proper conduct in the past, while the short-run gain from cheating today was less than the long-run benefit an honest coalition member could obtain. Since this situation was common knowledge, the merchants perceived that the agents could not do better by cheating. The agent acquired a reputation of being honest, the merchant could trust him. In short, the traders utilized a perpetuum mobile-the contractual relations among them reduced the transaction cost associated with agency relations and thus motivated each coalition member to follow these contractual arrangements. For this study I utilized a rich source of information on agency relations during this early period-namely, the geniza documents.9 A geniza is a place where Jews locked away writings on which the name of God was or might have been written. From about the ninth century on, a geniza room was located in a synagogue in Fustat (old Cairo), where for centuries tens of thousands of documents were deposited. The room and its contents were eventually forgotten until the end of the last century, when the treasure was rediscovered. 10 Although the 7 Note that a social control system and ethics mechanisms may constitute such a linkage. These mechanisms can thus be incorporated into the present approach. 8 The approach taken here builds upon theoretical developments in the economics of informa- tion, contract theory, and transaction-cost economics. See 0. Hart and B. Holmstrom. "The Theory of Contracts," in T. F. Bewley, ed., Advances in Economic Theory, Fifth World Congress (Cambridge, 1987); 0. E. Williamson, The Economic Institutions of Capitalism (New York, 1985); and others. For a pathbreaking historical application of these developments, see S. Fenoaltea, "Slavery and Supervision in Comparative Perspective: A Model," this JOURNAL, 44 (Sept. 1984), pp. 635-68. 9 For a general introduction to the geniza documents, see S. D. Goitein, A Mediterranean Society: Economic Foundations (Los Angeles, 1967), introduction; the entry "Geniza" in M. Th. Houtsma, ed., Encyclopedia of Islam (2nd edn., Leyden, 1978), vol. 3, pp. 987-89. 10 The documents were purchased by various libraries. Documents referred to here are denoted by the library in which they are located and their registration number within that library. When the reader is directed to a specific line or lines within the document, the side (a or b) and the lines are also mentioned. The following abbreviations are used: BM is the British Museum, London; Bodl. is the Bodleian Library, Oxford, England; DK is the David Kaufmann Collection, Hungarian Academy of Science, Budapest; Dropsie is Dropsie College, Philadelphia; ENA is the Elkan N. 860 Greif documents from the Fustat geniza are not the only geniza documents that have survived, they are identified simply as the geniza because of their value and volume. THE MAGHRIBI TRADERS AND TRADE EFFICIENCY The geniza contains more than one thousand documents which reflect the eleventh-century Mediterranean trade. These documents depict this trade as free, private, and competitive. The authorities' stance with respect to international trade reflected the tolerance and liberalism that characterized the period. Muslim rulers, especially the Fatimids (who ruled North Africa, Sicily, Egypt, and Palestine), sought to promote trade and no official restrictions fettered migration or the transfer of raw materials, finished goods, or money across the Mediterranean."1 Both transportation and mail delivery were competitive and largely private, and shipping was available even to a small merchant, who could rent storage space on a ship. 12 The trade within each trade center was free and competitive, with many buyers and sellers interacting in bazaars and storehouses, where they negotiated and competed over prices, using brokers, open-bid auctions, and direct negotiation.13 International trade was characterized by much uncertainty with respect to the duration of the ship's voyage, the condition in which the goods would arrive, the price at which the goods would be sold, and the cost of the goods. A journey from Egypt to Sicily, for example, could take from 13 to 50 days, and ships did not always reach their Adler Collection, Jewish Theological Seminary of America, New York; INA is the Institute Norodov Azii, Leningrad; Mosseri is the private collection of Jack Mosseri; Oxford is the Oxford library, England; TS is the Taylor-Schechter Collection, University Library, Cambridge, England; ULC is the University Library, Cambridge, England (exclusive of the TS collection). Many of the documents have been published by Goitein, Moshe Gil, and others. For published, translated, or quoted documents I cite the published source after the reference to the document. For example, TS xx.xxx, a, 11. 24-25, Goitein, Economic Foundations, p. 727 is a reference to document # xx.xxx in the Taylor-Schechter collection, side a, lines 24-25, that was published in Goitein, Economic Foundations, p. 727. " The entry "Fatimids" in Houtsma, Encyclopedia of Islam. Moshe Gil, Palestine During the First Muslim Period (634-1099) (in Hebrew and Arabic), (Tel Aviv, 1983), vol. 1, pp. 257-58; Goitein, Economic Foundations, pp. 29-35, 266-72; S. D. Goitein, Letters of Medieval Jewish Traders (Princeton, 1973), pp. 10-1 1; and A. R. Lewis, Naval Power and Trade in the Mediter- ranean, A.D. 500-1100 (Princeton, 1951), pp. 189 ff. Customs were imposed, but their levels were limited by competition between trade centers. How trade embargoes forced cancellation of a tariff is presented in A. Greif, "Reputation and Coalitions in Medieval Trade: Evidences from the Geniza Documents," MS, Northwestern University, 1989. 12 Goitein, Economic Foundations, pp. 309 ff.; Goitein, Letters, p. 112, n. 5; Moshe Gil, "The Jews in Sicily Under the Muslim Rule in the Light of the Geniza Documents," MS, Tel Aviv University, 1983 [also published (in Italian) in Italia Judaica, (Rome, 1983)], p. 27, n. 30; TS 16.7, b, 1. 5. For Europe, where the situation was rather different, see Gras, Business and Capitalism, pp. 40, 43, 76, and de Roover, "The Organization of Trade," pp. 48, 58 ff. For a discussion of mail delivery, see Goitein, Economic Foundations, pp. 191, 281-95. 13 Goitein, Economic Foundations, pp. 157, 187, 192 ff. Maghribi Traders 861 destination.14 Within the ship the goods were not well sheltered and were often damaged in transit. Furthermore, as the captain of the ship was not responsible for packing, loading, and unloading the goods, there was always the possibility that he or the crew would pilfer the goods.15 Although prices within each trade center were determined competi- tively, they were subject to large variations. The nature of the commu- nication and transportation technologies and in particular the length of time it took to deliver goods, and the limited capacity of the buyers to ship goods, made supply and demand in each trade center rather rigid. Any demand or supply shock thus led to a sharp change in prices. The price of flax in Sfax (Tunisia) around 1059, for example, fell from 70 to 40 dinars within a short period of time. The price of lead rose from 8 to 14 quarter-dinars following the arrival of 25 ships of buyers in Mazara (Sicily). 16 Because all of the countries between Spain and South Arabia formed a closely knit trading area, changes affecting business in one country were felt abroad. The general principles regulating the fluctuation of prices were well known to eleventh-century merchants, who tried to gather information and to update their business decisions accordingly. When one merchant learned that a large flax crop was expected in Egypt, he advised his business associate in Tunisia to sell all the flax he had as quickly as possible. The latter chose to sail to Sicily with the flax since he had been informed that the prices there were higher. In 1061 the price of wheat in Tunisia rose sharply when it became known that the Normans had conquered Messina (Sicily).17 The geniza documents utilized for this study relate mainly to a group known as the Maghribi traders. These were Jewish traders who lived in the Abbasid caliphate (centered in Baghdad) until the first half of the tenth century, when they emigrated to North Africa (a part of the Maghrib, the Muslim world's West), mainly to Tunisia. This region was prospering at that time under the rule of the Fatimid caliphate. Later, during the eleventh century, one finds Maghribi traders who emigrated 14 Ibid., pp. 273 ff.; termination in Libya instead of Sicily: TS 20.152, a, 11. 24-25, Gil, Palestine, vol. 2, p. 727. 15 See, for example, Bodl. MS Heb. c28, f. 61, a, 1. 6-7, Gil, The Jews in Sicily, pp. 126-33. On pilfering, see Bodl. MS Heb. c28, f. 61, a, 1. 12-13, Gil, The Jews in Sicily, pp. 126-33; Goitein, Economic Foundations, p. 157. On damage, see Bodl. MS Heb. a3, f. 13, Goitein, Letters, p. 122. 16 Dropsie 389, a, 11. 4-5, b, 11. 27-28, Gil, The Jews in Sicily, pp. 113-25. See also Goitein, Economic Foundations, pp. 301 ff. 17 TS Arabic box, 5, f.1, 11. 16-17, S. D. Goitein, "Jewish Trade in the Mediterranean in the Beginning of the Eleventh Century (in Hebrew)," Tarbiz, 37 (Jan. 1968), pp. 168-70. Wheat: INA D-55, No. 13, Goitein, Letters, pp. 163-68. See discussion in Goitein, Economic Foundations, pp. 200-1. 862 Greif from Tunisia to Spain, Sicily, Egypt, and Palestine. Some of them went as far as Byzantium and eastern Europe.18 The Maghribi traders were largely middle class. Although some of them invested in merchandise worth at least several thousands dinars- a considerable sum for a period in which middle-class household expenditures per month averaged less than three dinars-most were involved in business ventures worth no more than a few hundred dinars. The number of traders who operated during the eleventh century is not known; the several dozens of traders mentioned in the geniza clearly represent only a partial listing. 19 Although the Maghribi immigrants integrated into existing Jewish communities, they also retained a strong sense of identity and solidarity among themselves.20 In their letters they refer to themselves as "our people, the Maghribis, the travelers [traders]