1995.09.07, Duncan-Jones, Money and Government in the RE

M.I. Finley on the ancient economy can be quoted to support a variety of views. On the value of quantification in the study of the ancient economy, Finley warned against “number fetishism” that might lead historians “to claim quantitative proof where the evidence does not warrant it, or to misjudge the implications that may legitimately be drawn from their figures.” But he also called for “a shift in the still predominant concentration of research from individual, usually isolated documents to those that can be subjected to analysis collectively, and where possible over time.”¹ The former of Finley’s two pronouncements on the value of quantitative studies has found by far the more supporters. ² Among those who have challenged it, implicitly or explicitly, none has been more ambitious than Richard Duncan-Jones. His first book, originally published in 1974 and reissued in paperback in 1982 with corrections and additions, bears, uniquely to my knowledge among books on the ancient economy, the word “quantitative” in the subtitle. ³ As quantification goes in the study of more recent history, The Economy of the Roman Empire is not terribly quantitative; that is to say, its “quantification” resides mainly in the attempt to compile meaningful numbers about economic activity in the Roman empire, and also, in its most challenging and controversial chapter, to try to test numerically the validity of the profitability claims for various types of cash crop farming put forward in Columella’s Res rustica. ⁴ Duncan-Jones sought his numbers not in amphora or pottery distributions, which have long attracted numerically literate ancient historians, but in (for example) building costs and other prices in North Africa and Italy. While he may not always have given full due to the difficulties of his sources and the incommensurabilities of some of his data, his results were nonetheless profoundly interesting, and still, it seems to me, not fully absorbed by the scholarship. Duncan-Jones’ second book, which appeared in 1990, ⁵ ranged widely in issues in the imperial economy in a series of more or less independent studies on the speed and frequency of travel, the impact of government on patterns of trade, problems in demography, landed wealth and commodity prices, aspects of the urban economy, and the Roman tax structure. Some of these issues were explored using explicit statistical techniques, but in every case Duncan-Jones’ preference for asking questions that could be answered only with large bodies of data shone through.

Now, having turned his attention to the production and use of coins, Duncan-Jones has produced his most uncompromisingly quantitative book to date. In 59 figures, 110 tables, and 268 pages of dense and sometimes difficult text and appendices, he aims “to use coin evidence to study Roman minting policy, monetary organization, and the monetary economy” (xv). As a summary, this statement is slightly misleading. Duncan-Jones is interested only in coins produced by the Roman imperial government, and of those mostly the ones struck at the central Roman mint. Excluded from consideration are the very numerous and locally important issues in the west and particularly the so-called Greek imperials of the east. His studies—for in many respects the book is a collection of more or less independent examinations of particular issues that can be profitably explored through the coins—thus do not yield an understanding of “the” monetary economy, but only a part of it. But that part is a very important part indeed.

Duncan-Jones begins with the “budget” of the empire: expenses and incomes. He argues for cycles of surplus and deficit over the reigns of several emperors as attested by claims in the sources about the amount of money in the imperial treasury at the start of each reign, but these cycles tend sometimes to correlate rather uncomfortably with the historical tradition about each emperor: the bad ones leave the treasury exhausted, the good ones die with a surplus. (It is ironic to consider how little changes in the vocabulary of political rhetoric.) Duncan-Jones is on better ground with his study of imperial expenses: he shows, quite concretely, that army pay absorbed the vast majority of imperial funds, and how that cost grew over time (see especially table 3.7). So far the book has not really said anything very new, although conventional knowledge is put on a much better quantified basis than before. It is when he turns to the coins, which constitute his main body of evidence, that Duncan-Jones offers his first real discovery, on which the rest of the book depends.

Millions of coins survive from the empire, but Duncan-Jones is only interested in those found in hoards. Typically, coin hoards have been seen as representative of “coin in ordinary private ownership, either drawn from current circulation (‘circulation’ hoards) or accumulated over an extended period (‘savings’ hoards)” (67). Studying a sample of 230 hoards with a minimum value of HS 400 (cited in Appendix 10, 261-266), Duncan-Jones has noticed that these hoards tend (1) to cluster around a few sizes, (2) to contain only one denomination, (3) to cluster chronologically, and (4) to cluster in heavily garrisoned frontier provinces. From these characteristics, Duncan-Jones argues (convincingly, to my mind) that “the special characteristics already seen in the hoard-sample do not seem compatible with the casual private accumulation of money. Instead, they argue a pattern of amounts and a pattern of events imposed on the empire as a whole, not merely on single regions. Finds of coin in a single denomination … almost inevitably look like army payments” (78). He can then connect hoards dated by their last issues to specific payments, whether regular pay ( stipendium), retirement pay ( praemia), or donatives ( donativa). This connection provides the link to key the abundant information that can be extracted from the hoards by statistical investigation into the economic and political history of the empire. The rest of the book is devoted to extracting, elucidating, and evaluating that information.

The results are rich and impressive, if not all equally convincing. Duncan-Jones estimates mint production as roughly HS 170-200 million per year, about a quarter of the total budget (c. HS 800 million/year). He shows that variations in content of hoards reflect variations in production at the mint; in this context, however, we find that stray finds of gold coins actually better represent mint output than the contents of hoards, a troubling result not fully explained (115-120). Study of the output of individual reigns reveals interesting patterns; not surprisingly, output is high at the start of a new reign, when demand for cash is high. When different members of the imperial family coin simultaneously but separately (as in the “Empress” issues struck under Hadrian, Antoninus Pius, Marcus Aurelius, and Commodus) silver output tends to fall into integer ratios like 2:1 or 4:1 (140-142); this very interesting result is demonstrated but not accounted for. The chapters on “The Size of Die-Populations,” which estimates the total numbers of dies used for various issues (2000 a year for silver and 25-50 for gold under Hadrian, for example), and “The Size of Coin-Populations;’ which treats the productivity of dies, contain much of great interest to numismatists, including new techniques for making these estimates. Historians who see the economy of the empire as unified by the circulation of specie will want to read carefully Duncan-Jones’ results on the mobility of the coins and circulation speed which argue an economy both regionalized and far more sluggish than other pre-modern European economies (172-192). Low rates of wastage confirm these results. Reminting of older silver, which may have been in circulation for a very long time—Republican silver was reminted under Trajan—was undertaken, predictably, for profit. It is however very curious in this context that Britain shows a different pattern, Republican silver continuing to circulate into Hadrian’s reign; once again, this interesting anomaly is described but not explained (192-212). Finally, Duncan-Jones demonstrates clearly the process of debasement of the metal content of the coins, a process that went on in a virtually uniform trajectory from the later years of Nero’s reign to the third century (see especially 230-231 tables 15.7 and 15.80. At the same time, due weight is given to variations in weight and quality that resulted entirely from technical limitations of ancient mensuration and quality control (238-247).

On the way are dozens of striking observations and bouleversements of conventional opinion too numerous to recount here; as an example, consider the flow of coined money in the empire. Duncan-Jones’ remarks on this issue effectively undercut Keith Hopkins’ view of the imperial budget as a cycle that brought wealth into Rome from the core provinces as taxes to be redistributed as army pay to the frontiers. ⁶ Duncan-Jones shows that instead most coin tended to stay close to where it was first disbursed, that is to say, monies paid out in Gaul tended to stay in Gaul rather than wander back to Rome as tax payments. The slow speed of circulation of coins reinforces this view, which favors seeing the empire as divided up into many more or less self-contained regional economies, rather than a single, unified system. Duncan-Jones’ tightly argued and strongly supported views pose a real challenge to those who see the economy of the empire as such a unified system. Typically, Duncan-Jones does not mention these views, nor the evidence—mainly the distribution of pottery—on which they rest. ⁷ There are real problems to be settled here, although I have my doubts whether they will receive the attention they deserve, partly because folks who work with the material remains and historians like Duncan-Jones still do not talk to each other as much as they should, ⁸ and partly because of the character of Duncan-Jones’ book, which will surely put off many readers (see below). It is worth noting in this context that, sauf erreur, the words “primitivist” and “modernist” do not appear in the book.

It is refreshing to see ancient economic history treated with statistical rigor. Duncan-Jones’ grasp of statistical method is sure, his figures and tables appropriate and readable, though not always provided with full explanation. I for one wish he had regularly provided the r ² for his fitted lines, which would have helped the reader distinguish convincing fits from the few that are surely meaningless (figure 14.6, whose very poor r ² of 0.380 is buried at 201 n. 36). At Appendix 8 he even prints two programs written in BASIC for determining binominal k and estimating die populations. (I must confess I did not try them, but there seems to be a misprint in Program 1, line 50 1p. 2591, where “IF C > 0.8” should surely read “IF C < 0.8.")

This is an uncompromising and sometimes unnecessarily difficult book. Duncan-Jones offers only the barest summary of his intentions (xv, quoted above) and nothing like an overview of his argument. The reader must plunge in without preliminary orientation, and it is not always easy to see where the argument is headed, especially in the first few chapters. A few pages devoted to laying out the argument to follow would have been a tremendous service, especially as the discussion can sometimes become highly technical. Duncan-Jones’ terse prose rarely leaves space for digressive explanation, and it is my guess that the reader to whom r ² and negative binominal k distribution are, well, not Greek will often feel completely at sea. A few words of explanation in non-technical language might have provided these readers the encouragement they need to press on; as it is, the demands Duncan-Jones makes on his reader will surely lose him many among the book’s natural readership: the professional historian of the Roman empire. Its emphasis on coins as evidence rather than as objects (Duncan-Jones solves no outstanding numismatic problems) will make it of marginal interest to professional numismatists (with the exception of those interested in the estimation of die numbers and life, to which matters Duncan-Jones makes important contributions); the virtual absence of any discussion of archaeological evidence may put off economic archaeologists.

I also wish that Duncan-Jones had engaged explicitly some of the views of the imperial economy, very different from his own and challenged by his book, that command widespread adherence. Subtle allusions here and there make it clear that he is perfectly aware of these other opinions, and of course he has already addressed these questions in part in Structure and Scale in the Roman Economy, which includes an extremely important essay on the distribution of lamps. His work in the new book pushes these issues much further, and it would be very interesting to see how—and whether—he would reconcile these views with his own and how he would evaluate the archaeological and ceramic evidence. These matters will have to be worked out, but we will have to proceed without Duncan-Jones’ guidance.

Quibbles aside, Duncan-Jones has written an important and challenging book that deserves to be widely read. The economy of the Roman empire remains endlessly fascinating, not least because of the broad range of evidence that can be summoned to testify. We are still very far from the day when someone will be able to write the book to replace Michael Rostovtzeff’s classic but long outdated The Economic and Social History of the Roman Empire, but whoever does will owe a great debt to the work of Richard Duncan-Jones, to which Money and Government is a fitting new contribution.