2.4.1. The specialization and efficiency framework for quarry studies

The most thoroughly-articulated efficiency model is the one developed by Torrence during her dissertation work on the Greek island of Melos (Torrence 1981;Torrence 1986). Her approach at the obsidian quarries of Melos focuses on lithic reduction sequences in order to detect the changes in morphology of flakes that point to increased specialization due to standardization of reduction strategies. Her goal is to establish "a framework for measuring exchange" by developing a continuum for production efficiency that aims to link particular levels of efficiency with the social correlates that indicate the existence of different forms of exchange. Citing Rathje (1975: 420-430), Torrence approaches the study of long-term changes in the efficiency of extraction and manufacture in terms of sophistication of technology, simplification, standardization, and specialization (Torrence 1986: 42). In her research she is able to establish a continuum of efficiency starting with the irregular, non-specialist production on one end, and high efficiency production characterized by ethnohistorical evidence from modern gunflint knapping, on the other end.

Characteristics of prismatic blade production facilitate the kind of examination for efficiency and specialization used effectively by Torrence. First, core-blade reduction sequences leave relatively visible evidence of the technical stages for archaeological analysis. Secondly, prismatic blades are extremely efficient as measured experimentally using cutting-edge to weight ratios (Sheets and Muto 1972). Finally, archaeologists have developed measures of error rates for obsidian blade production with the aim of establishing the degree of knapping expertise from debitage, and these measures correlate with efficiency gauged in both time and consumption of material (Clark 1997;Sheets 1975). These efficiency measures are relevant in areas with blade production, but they are not applicable to research in areas with exclusively bifacial reduction traditions, such as in the south-central Andes.

The efficiency measures that Torrence develops in her approach linking production with exchange has the advantage of being explicit and comparable across regions. Further, her measures of production efficiency complement the formal assumptions that underlie the fall-off curves used to analyze regional exchange models in an evolutionary approach that projects greater efficiencies in organization through time. That is, specialized blade production is the most efficient means of producing cutting implements, and freelance trade in a market based economy, following Polanyi's schema, is the most efficient means of moving goods to consumers. Efficiency measures have heuristic value, as divergences from expected efficiency models can prompt the pursuit of theoretical inquiries into the cause of the deviance from the anticipated efficiency models.

The most problematic aspect of this framework is the dependence on the theoretical link connecting efficiency measures to prehistoric institutions (Bradley and Edmonds 1993: 10), particularly in light of the substantivist/formalist debate in anthropology specifically referencing gifting and exchange relationships. Bradley and Edmonds (1993: 10) observe that, as with Renfrew's regression approach, the problem of equifinality undermines the system of inference when the principal link between production efficiency and elaborate institutions is reduction evidence from workshops. They question the supposition that larger socio-political structure and evolutionary stages can be reconstructed from the limited perspective of workshop production and regional distribution patterns based largely on consumption sites that often have poor temporal control and few contextual associations.

More recent studies have pursued another direction and have avoided comprehensive formal "frameworks" in favor of more willingness to incorporate case-specific details, social dynamism, and historical factors in developing social models of exchange (Friedman and Rowlands 1978;Hodder 1982).

Formal, cost-minimizing assumptions about human actions and incentives have provided archaeologists with a much-needed analytical structure to the study of prehistoric exchange, but critics note that it cannot provide a complete picture of ancient economies.

As Hodder notes, most studies have been predicated on the idea that progress can be made by assuming that people in the past considered costs and benefits along formal economic lines (Hodder 1982). Torrence's (1986) study is a case in point, for it is only by making this assumption that she is able to apply the same scale of measurement to people as different from one another as hunter-gatherers procuring workable stone for their own use, and the makers of gunflints for sale in the modern world market (Bradley and Edmonds 1993: 10).

A formal approach can serve as one of the layers in a more comprehensive analysis that also integrates finer scale social factors as well as historical particulars into the analysis.