Beginning with settlement pattern studies explored by Julian Steward, processual archaeologists often assume regional perspectives that emphasized social and organizational processes (Willey and Sabloff 1974). Building on Polanyi's observation that fundamental aspects of human institutions are economic, archaeologists understood that documenting the regional distributions of artifacts resulting from prehistoric mobility or exchange could contribute to reconstructing past societies. Archaeologists can use direct evidence from the production and consumption of archaeological materials and inference about the likelihood and form of prehistoric exchange to point to the institutional contexts of the ancient economy.

In Polanyi's (1957) seminal article outlining the substantive approach, "The economy as an instituted process," the economy is characterized in terms of two linked properties. First, there is the material process by which items are produced, circulated, and consumed; second, there is the economic form organized around socio-political relationships that arranges interactions diachronically and spatially. In this context, institutions serve as rules and obligations connecting human organizations around the process of producing and circulating goods. The implication is that an archaeological study of variation in prehistoric economies requires that archaeologists can document differences in the institutions that structured past economies.

Many contemporary theoretical approaches downplay the importance of structural analyses in favor of agent-based models, however anthropologists using New Institutional Economics (North 1990) are emphasizing the interdependence of institutions and economics and the implications for activities of individuals (Acheson 2002;Ensminger 2002). Douglass North (1990: 3) defines institutions as "the rules of the game in a society or, more formally, the humanly devised constraints that shape human interaction". This view considers how institutions developed from the decisions of individuals over long periods of time, affecting transaction costs through the benefits of coordinated activity. "Based on the advantages of lower transaction costs in commodity flows, [these anthropologists] argue that political and social institutions developed to regulate commodity flows, maintain regional peace, and guarantee contracts" (Earle 2002: 82). In this perspective, institutional complexity developed as rules to govern the economizing nature of individuals, and the emergence of such institutions should be correlated with increasing quantities of commodity exchange in prehistory. The perspective that argues that volume of exchange should correlate with increased social complexity has roots in theories of progressive evolution (Childe 1936), adaptionalist views (Steward 1955), and the managerial role of chiefs (Service 1962).

However, a positive correlation between evolving institutional complexity and a uniform increase in volume or variety of exchange in prehistory is not supported empirically (Brumfiel 1980;Hughes 1994;Kirch 1991). That is, contrary to the evolutionary expectations of some theorists, the volume or variety of goods transferred does not necessarily reflect the political or institutional complexity in a given society. Perhaps some of this inconsistency is the result of elite control of the circulation of commodities as proposed by Appadurai (1986: 38). Earle (1994: 420-421) observes that on the whole, the archaeological evidence is characterized by a great deal of variability in the types of goods exchanged, the volume of exchange, and the social contexts of exchange. In order to address this variability in an evolutionary framework, Earle suggests that exchange should be considered in terms of two categories, the subsistence economy and the political economy[1](Johnson and Earle 2000), with exchange taking different forms in each category of the economy. The exchange in these two forms of economy correspond largely to the distinction discussed earlier between ordinary goods and prestige goods where, according to Earle, political strategy is advanced by elites by, among other things, the manipulation of exchange relationships.

In a non-evolutionist application of New Institutional Economics in anthropology, Wiessner (2002: 235) differs from North in arguing that transaction costs for exchange are actually high in small-scale societies due to the close relationship between social and economic transactions; there is less neutral space for "unembedded" economic behavior with their associated overhead costs. In such contexts egalitarian institutions developed to foster trust and make interactions more predictable.

In non-market economies in which kin-based exchange systems play an important role in reducing risk (Wiessner 1982;Wiessner 1996) the goal of exchange is to be covered in times of need. In this context, the social and the economic are closely intertwined (Mauss 1925) and it is undesirable for returns to be stipulated as to time, quantity, or quality (Sahlins 1972). The most valuable information in such exchanges is the details of the partner - what he or she has to offer and will offer over the long run (Wiessner 2002: 235).

Elaborate institutions regulating behavior are not new, argues Wiessner, but if there is a weakening in the egalitarian prohibition against the accumulation of wealth or power the "alchemy of ambition" (Wiessner 2002: 234) drives a few individuals to seek preferential access to resources. In contexts of regional packing and circumscription it is argued that hierarchies emerge (Brown 1985;Johnson 1982) that are perhaps founded on the control of labor and surpluses, and instituted through ritual (Aldenderfer 1993;Hayden 1995)

Materialist perspectives hold that economic gains are used to bring about changes in the social order, and that these changes are then legitimized and perpetuated through ideology. These economic gains are generally achieved through intensification of production and through finance organized by ambitious individuals (Boone 1992;Earle 1997;Hayden 1995). Clark and Blake (1994: 17), building on practice theory (Bourdieu 1977;Giddens 1979), describe a model whereby institutionalized inequality is the unintended outcome of political actors competing for prestige by using strategies that match the self-interests of their supporters. Ultimately, these strategies may develop into redistributive institutions that appear to build on the social-leveling mechanisms described by Wiessner (1996), but operate on a larger scale and result in political advantage for redistributing leaders and their allies. In other words, it is institutions themselves that form the basis for leveling mechanisms, and it is institutions that are transformed into vehicles that serve to, in part, legitimize social inequalities.

An important temporal component to exchange is connected to institutions as well because transactions involve anticipation and scheduling. As Colin Danby (2002) argues, most transactions in neoclassical economic analyses in anthropology are considered as synchronic "spot transactions" of commodities, while long term interpersonal relationships enter the domain of gifts in a gifts: commodities dichotomy. The temporality of reciprocation is a means by which economic transactions are embedded inside of social calendars, but various socially-mediated methods of extending credit are well-established and probably an ancient manner of precipitating exchange in market-based transfers as well.