The study of ancient economies has long been a central theme in archaeological research. Lying at the intersection of human behavior and material goods, economy can often provide a theoretical basis for connecting features and artifacts with larger scale traits in prehistoric societies. Economic approaches to prehistory have the promise of bridging the premodern individuals and institutions of anthropological study with their material remains in a quantifiable way in order to examine processes such as change in subsistence, intensification, and exchange.
A fundamental question in economic anthropology concerns the cross-cultural applicability of economic models developed primarily for explaining behavior in Western, market-oriented societies. In the past 50 years economic anthropology has witnessed protracted debates between advocates of formal and substantive approaches to economy (Plattner 1989: 10-15). The perspective put forward by formalists is that ancient and non-western societies differ from those of modern capitalist societies in degree but not in kind (Wilk 1996). In contrast, substantivists recognize fundamental differences between ancient or non-capitalist societies and modern economies. These debates have been reconciled to a certain extent with the recognition that the two approaches largely complement each other. The distinct assumptions associated with formal and substantive economics, however, are critical to framing research questions about ancient economy, commodities, and exchange.
Formal approaches explore the outcome of rational decision-making with regard to choices faced by prehistoric populations. By conceiving of economic behavior in terms of universal rationality, these approaches are analytically useful because they allow for the isolation of variables and for cross-cultural comparisons. Formal economic analyses are built on studies of modern markets by human geographers and involve reducing labor, land, and capital to the price as the unit of cost. Anthropologists using formal approaches may apply energy or time as value units to studies of food procurement, raw material provisioning, and settlement choice as in studies by behavioral ecologists (Winterhalder and Smith 2000) and archaeologists (Earle and Christenson 1980;Jochim 1976;Kennett and Winterhalder 2006).
Formal approaches to prehistoric exchange have been used by archaeologists to study the evolution in exchange systems both organizationally and from the perspective of individual behavior (Earle 1982: 2). On the larger scale, regression analysis (Hodder 1978;Renfrew 1977;Renfrew, et al. 1968;Sidrys 1977) and gravity models (Hodder 1974) use assumptions of cost minimization to differentiate between possible exchange systems in prehistory. "The sociopolitical institutions establish constraints in terms of the distribution and value of items. Then, individuals, acting within these institutional constraints, procure and distribute materials in a cost-conscious manner" (Earle 1982: 2). Neoclassical assumptions on the scale of individual behavior have also been used to examine the evolution of market based exchange (Alden 1982) and subsistence goods exchange by territorial groups exploiting high-yielding yet unpredictable resources (Bettinger 1982). A synthesis by Winterhalder (1997) investigates the way in which complex exchange behaviors that have been documented ethnographically can result from models of circumstance such as tolerated theft, trade and risk reduction, and models of mechanism such as kin selection and dual inheritance.
Critiques of formal approaches have been various, with strong methodological criticism coming from influential ex-formalists like Ian Hodder. On the subject of exchange, Hodder (1982: 202) observes that the explanatory power of formal approaches to prehistoric exchange are significantly weakened by the problem of equifinality in the empirical evidence, an issue discussed below. Hodder further argues that middle range links between social contexts, political strategies, and the empirical evidence provided by distributions of archaeological data are insufficiently accounted for with formal approaches such as regression analysis.
Substantivism arose in anthropology largely in response to what was perceived as the inapplicability of formal approaches and the assumptions of neoclassical economics to ethnographic case studies (Wilk 1996: 1-26). Substantive approaches emphasize that economy and exchange are fundamentally linked to other aspects of human behavior. To substantivists, economic institutions are effectively cultural traits, therefore techniques designed around "modern" or "western" conceptions of rational individualism are inadequate for application in non-western cultural contexts (Bohannan and Dalton 1962;Dalton 1969). The position was first articulated by Karl Polanyi (1957) that the economy is "embedded" in sociopolitical institutions. This view of economy and non-western exchange has its roots in studies by Malinowski (1922) and Mauss (1925), although the focus in that earlier period of economic anthropology was on social relationships, whereas social change dominated the discourse in economic anthropology during the 1960s (Dalton 1969).
Mid-twentieth century substantivism was based on a functionalist view of society as static and aspiring to the maintenance of equilibrium within the social environment (Schneider 1974). Interaction took place through reciprocity, redistribution, and exchange. Sahlins' (1965) further elaborated on reciprocity based exchange by placing generalized, balanced, and negative reciprocities along a continuum that served to describe the dynamics of interaction within specific social contexts. Another distinction lay between the transfer of inalienable gifts between reciprocally dependent individuals "that establishes a qualitative relationship between the transactors" (Gregory 1982: 101) and alienable commodities as transfer between reciprocally independent people "that establishes a quantitative relationship between the objects exchanged" (Gregory 1982: 100).
A number of critiques have emerged of the substantivist approach. One critique of substantivist approaches to exchange, one that is true of functionalism more generally, is an early version of agency theory. In the substantivist view, society is constructed of consistent rules within agents must act and includes a moral obligation of exchange (Dalton 1969: 77). In this organic perspective, however, "[t]here is little room for individual construction of social strategies and manipulation of rules, and there is little intimation of conflicts and contradictions between interests" (Hodder 1982: 200).
A second critique focuses on the distinction drawn by substantivists between complex and small-scale societies. Among complex societies, formal approaches are supposed to be more relevant, but in the context of small-scale societies substantive approaches are appropriate, and this dichotomy creates a dilemma of where exactly to draw the line. Monica L. Smith (1999: 111) argues that the ethnographic cases to which many substantivist models refer (i.e., small-scale societies) are lower in population density and involve fewer layers of interaction than would have been found in premodern states and empires and therefore formal approaches might have more relevance in premodern complex societies than is presented by substantivists.
A third critique holds that the direct correlation between forms of exchange and level of socio-political complexity lacks empirical support (Hodder 1982: 201). Anthropological studies suggest that unpredictability in food supply correlates with more extensive reciprocal exchange systems. Reciprocity is encountered more frequently among hunters, fishers and farmers than among gatherers and pastoralists who exploit relatively predictable resources (Pryor 1977: 4).
In the current day, Polyani's framework centering on the distinction between reciprocity, redistribution and market forces continues to be widely used in anthropology and archaeology, despite the development of alternative models that are particularly relevant to studies of commercialized pre-modern states. In particular, Michael E. Smith (2004) argues that more refined differentiation of transaction mechanisms can be used to distinguish the degree of internal and external commercialization in state-level societies, such as those presented by Carol A. Smith (1976). However, the subtleties of ancient commercial enterprise are less relevant in places like ancient Egypt and the Andes where historical and archaeological evidence attest to strong state control of uncommericalized economies without market-based economics, money, and independent merchants. In other words, Polyani's coarser distinctions of reciprocity, redistribution combined with non-market trade are sufficient in regions such as the ancient Andes where most scholars believe commerce played an minor role in prehistoric development (LaLone 1982;Stanish 2003). In Mesoamerica, however, where evidence for prehispanic markets and traders is widespread, anthropologists have found that Polyani's distinctions are vague and that models with further refinement in modes of commercialization are applicable (Braswell 2002;Smith 1976;Smith 2004).
Formal and substantive approaches can be applied in a complementary manner. For example, in Stone Age Economics, Sahlins (1972) attempts to explain the existence of supply and demand curves among aboriginal exchange networks where social parameters determine the development of exchange. Winterhalder (1997) discusses some of the concepts presented by Sahlins (1972) using a behavioral ecology approach to gifts and exchange among non-market foragers. Winterhalder finds that issues such as social distance can be addressed more explicitly in a formal framework, albeit more narrowly, because economizing, neoclassical assumptions are a starting point for this type of analysis. As Hodder (1982: 200) points out, formal and substantive approaches are targeting different behaviors; formal economics relies on outputs and performance, while substantive analyses relate to social contexts of exchange.
While these differences make the two approaches irreconcilable on some levels, some studies attempt to integrate both avenues of research. Drawing on the advantages of both formalism and substantivism may be worthwhile, but a tendency to apply formal analyses to state-level societies, due to greater commercialism and specialization, and to apply substantive analyses to small-scale societies, should be resisted (Granovetter 1985;Gregory 1982;Smith 1999). The assumption that in premarket social contexts economic behavior is heavily embedded in social relations, but then is increasingly atomized and conforming to neoclassic analyses in modern, market-oriented societies is inconsistent. Granovetter (1985: 482) writes
I assert that the level of embeddedness of economic behavior is lower in nonmarket societies than is claimed by substantivists and development theorists, and it has changed less with 'modernization' than they believe; but I argue also that this level has always been and continues to be more substantial than is allowed for by formalists and economists (Granovetter 1985: 482).
Similarly, Danby (2002) observes that there are serious logical flaws in the false dichotomy, widely applied by archaeologists, where neoclassic, cost-minimizing logic is applied to premodern, complex societies but increasingly assuming an embedded "gift" economy among smaller-scale economies.
This dissertation research project follows on the substantivist tradition in the Andes, but formal approaches have been influential in exchange studies worldwide. The weaker elements of the substantivist approach will be avoided by not assuming a direct correspondence between socio-political complexity and volume or type of exchange.