Markets are of particular interest in this discussion because while market principles, to a certain extent, underlie all formal economic approaches in anthropology, market-based economies are far from universal in the premodern world, even among state-level societies. A basic definition of a market is "the situation or context in which a supply crowd (sellers) and a demand crowd (buyers) meet to exchange goods and services" and where the market principle is operating (Dalton 1961: 1-2). Three characteristics used by Earle to evaluate the evidence for market-based exchange in the Inka state include: (1) The importance of specialized institutions of production and exchange divorced in their operations from other institutional relationships; (2) The development of a medium of exchange to facilitate the systematization of exchange values; (3) The percentage of goods utilized by a household that are obtained by exchange (Earle 1985: 372-373).

The presence of exchange institutions, either as bustling marketplaces or distributed as "site-free" exchange houses, have a characteristic described by Earle (1985: 373) as a context where "non-exchange relationships, such as kinship and political ties, will not unduly constrain choice". The alienability of products, the strong influence of price motive and the detachment from production and other social linkages, underlie many of the features of these proposed institutions. The consensus among Andeanists is that during Inka domination, and probably during the preceding periods, market-based economies were not found in the central and southern Andes with a few exceptions (Earle 2001;LaLone 1982; but see href="/biblio/ref_2005">Salomon 1986;Stanish 2003).

The location of transfer becomes important with respect to price-fixing markets. In aggregations the public nature of the contact and the circulation of information is quite different from isolated exchanges. These issues are linked to the spatial and temporal configuration of exchange in market economies because just as periodic gatherings, central places, and rank-size geographic relationships serve to distribute goods in some settlement systems, these aggregations serve to distribution information about availability of products and changing prices to buyers and sellers (Smith 1976;Smith 1976). When exchange takes place in a private courtyard rather than a public marketplace then there is reduced risk of the neighbor overhearing the barter exchange value offered to another (Blanton 1998;Humphrey and Hugh-Jones 1992). Greater public visibility and monitoring in market contexts might be expected, and greater privacy, interpersonal negotiation, and temporal depth to exchange relationships in private barter exchange configurations.