Premodern Japanese history, especially for the eras prior to 1600, is not a large field, and those who seek to illuminate the economic history of any part of this period comprise a substantially smaller number of scholars. Nonetheless, concern with the development of coins and currency represents a persistent and challenging theme. Within this context Ethan Isaac Segal's work represents only the second book-length study of this subject in English. The limited attention to money and pre-1600 economic development results not only from more than the small number of tillers in the field, it is also a function of limited and challenging sources and a general impression that efforts to introduce coinage did not really take off until the economic growth of the Tokugawa era (1600–1868). Segal, Associate Professor of History at Michigan State University and a protégé of economist Kozo Yamamura, takes on these demanding circumstances, exploits analyses of land sale contracts, legal records, donations to temples and shrines among other data to argue for a more important and widespread role for money in an ancient and medieval economy, one that was expanding and diversifying even as it fell considerably short of its early modern (Tokugawa) counterpart. Segal contextualizes his study with comparisons to Europe, China and other parts of Asia as well as more theoretically oriented work. Occasionally spiced with reference to folk and other tales, the study is accessible to generalists and comparativists as well as Japan specialists.

Segal places special emphasis on the period from the twelfth century, from which he dates a widespread shift away from commodity monies to metal currency. Contesting the common perception which emphasizes government initiative, he argues that this transition took place outside of central government control. He sees changes in the economy as opening up opportunities for provincial forces to expand their economic activities, activities facilitated by the use of currency. In response to these changes, provincial political forces were more likely to ride the new economic wave than those closer to the center. The author lays the groundwork for this argument by exploring early (seventh to eleventh centuries) efforts to follow the Chinese model of currency, its successes and limitations.

Examination of economic institutions occupies the core of Segal's analysis, an inevitable approach given the lack of statistical data for the era. He begins with a discussion of the very earliest efforts to issue coinage based on Chinese models, a pattern that persisted as a focus of the central government through the twelfth century. Chapter 2 shifts attention to provincial organizations, their economic activities, and use of mediums of exchange.

Among the interesting explorations, one (chapter 3) concerns the laws of “virtue” issued by early medieval authorities. These debt-cancellation edits, he suggests, co-opted an aristocratic concept of rule that originally had nothing to do with such measures. Chapter 4, focusing transformation of provincial demands for more flexible methods of exchange, takes up second development, the emergence of bills of exchange as a means of transmitting funds long distance. Chapter 5 moves beyond Segal's main chronological focus to examine economic growth, diversification, and transformation in the fourteenth to sixteenth centuries.

Central features in the development of coinage in medieval Japan lie in both the Imperial government's lack of interest over the tenth and twelfth centuries and its loss of administrative authority altogether over the twelfth through fourteenth centuries, a loss in many respects unfilled by the authority of the Shoguns even before it, too, fell apart entirely in the late fifteenth century. Such circumstances created two particularly awkward problems for growth in the use of currency, one of supply and the other for the use of bills of exchange. No central government produced coins for much of this time nor did it (or could it), like medieval Chinese “flying money,” guarantee paper scripts.

In the face of limited central authority, Segal makes the ingenuity of nongovernmental actors clear: Since the government was not actively promoting the use of coins after the twelfth century, any increased demand had to be met from sources other than government mints, and imported Chinese coins filled that void. In the development of bills of exchange, private mechanisms to ensure transmission had to be developed. This process involved small-scale “test” exchanges designed to assure that trust in a purveyor of transmission services was warranted, an important consideration.

Segal has scoured diverse sources for data and has pieced together an intriguing argument. His inescapable reliance on qualitative data prevents exploration of some questions of interest to economic historians. Others will not be answered to the satisfaction of those who want quantitative data. Nonetheless, Segal has given us much of value and much to think about.