Intrasite variability in lithic distributions, and the morphology of those artifacts, can shed light on exchange patterns. Several projects in Mesoamerica have inferred redistribution as the mechanism of exchange when concentrations of non-local lithic materials at major sites point to debris associated with specialist workshops and other kinds of intrasite use of space. Blade manufacturing debris has been used in this manner at Tikal (Moholy-Nagy 1975;Moholy-Nagy 1976;Moholy-Nagy 1991;Moholy-Nagy 1999), the Basin of Mexico (Sanders, et al. 1979), and Teotihuacan (Spence 1967;Spence 1984).

The proportion of artifact forms of a non-local material in a single site has been used to characterize mechanisms of exchange. This approach has proved useful with obsidian exchange in places where distinctive reduction strategies are associated with finished artifact form, such as blade technology, and these strategies can be recognized in lithic material found in consumption sites. Winter and Pires-Ferreira (1976: 309-310), working at two sites in Oaxaca, argued that blades of high quality, non-local obsidian were introduced to the sites in finished form and that this constituted evidence of elite pooling for prismatic blade reduction followed by redistribution to local sites. The higher quality material was transformed into more valuable artifact forms in workshops located outside of their study area, and then in the Oaxaca sites the presence of these artifacts that were apparently the result of contact with elite spheres of exchange, was interpreted as evidence of redistribution of the finished artifacts. The sourcing and exchange work of Pires-Ferreira has come under some criticism because in her initial proveniencing study she only used two diagnostic chemical elements, and more recent analyses suggest that many of her sourcing attributions are incorrect (Clark 2003: 32). Further, Sheets (1978: 62) argues that the edges of prismatic blades are too fragile to have been transported in completed form (Clark and Lee 1984: 272).

Systematic studies of the intrasite contexts and artifact form of non-local material have the potential to provide insights into exchange and social structure. Intrasite spatial patterns can be investigated in combination with both quantitative data stemming from geographical distances and artifact abundance, and with qualitative data inferred from artifact form and technological aspects of production (Torrence 1986: 36). These kinds of intrasite patterns are susceptible to distortion by dumping patterns and intrasite studies must be sensitive to the problems of conflating material from workshop refuse, household middens and construction fill (Moholy-Nagy 1997).

In a useful review of Mesoamerican obsidian studies Clark (2003: 32-39) summarizes major advances in provenience and trade models, and highlights important avenues for improvement. One important observation made by Clark is that in archaeologists' efforts to design systematic approaches to exchange, early studies failed to distinguish "power as energy and power as legitimacy" (Clark 2003: 38). It could be argued that these forms of power are largely comparable, as the ability to procure, display, and redistribute non-local goods demonstrates power in both energy and in prestige. However, as was emphasized by substantivists in their discussion on the inalienability of certain products, the value of particular status items rests precisely in their incommensurate nature.

Sanders and Santley's (1983) proposal that special goods were returned to Teotihuacan in exchange for obsidian products, and that these were cashed in for corn from the fringes of Teotihuacan's domain in hard times, fails to appreciate that once symbolic goods circulate like economic goods among the hoi polloi such goods lose any legitimizing powers (Clark 2003: 38).

A framework for investigating prehistoric exchange must negotiate between these features of the archaeological record. Material evidence of long-distance exchange is abundant and easily measured, but interpreting the significance and perceived value of these non-local products in the social and political context of their consumption is the measurement of greatest relevance to comprehending the role of exchange over time.