Regional exchange is of particular utility to anthropological archaeology because it is a material phenomenon that occurs at the intersection of social relationships, resource procurement, and individual or community differentiation. However, exchange has been attributed with great causal significance in the past and, while it provides evidence of particular utility to anthropologists and archaeologists, it is important to not ascribe excessive significance to exchange in human affairs. For example, to V. Gordon Childe (1936) long distance trade was a prime mover that had direct social evolutionary consequences. Engaging in trade had derived benefits that can affect the balance of power between competing polities and stimulate larger forms of organization.

In the 1970s, Rathje (1971;1972) proposed that it was the lowland Maya need for "essentials" like obsidian, salt, and grinding stones that propelled them to seek external sources for these scarce goods, initiating long-distance relationships. Those who control access to scarce materials accrued benefits from their position in the trade network, he argued, and hierarchies emerged from the differential access to these required, or desired, trade goods. Virtually all of Rathje's postulates have since been disproved, but some variant of the theme first articulated in Rathje's exchange model underlies many contemporary investigations of ancient trade (Clark 2003: 33-34).

In the multilinear evolutionary framework of Johnson and Earle (1987), trade is part of an array of processes that are relevant to socio-political development, but trade does not become a dominant process until the formation of the Nation-State.

Table 2-2. Economic processes in political evolution (Johnson and Earle 1987: 304) where capitalized words indicates a dominance of that process, parenthesis indicate important secondary processes.

The approach taken here is that all human groups engage in exchange in some form and it therefore serves as a consistent index of regional relationships through time. Furthermore some trade items, such as obsidian, appear to have been part of a suite of features that, at particular times and socio-political contexts, serve to differentiate individuals or groups from the rest of their community for purposes relating to political strategy. While exchange is not a prime mover for socio-political change, transfer between peoples and groups in different forms provides a vehicle for social differentiation and a materialization of geographical relationships that are closely linked to socio-political organization. Thus, while one may see exchange occurring over the long term, it is not a prime-mover but it is changes in evidence of production, transfer, and consumption of non-local goods that inform theoretical models of prehistoric change.