Ancient economy in the Andes has been most fruitfully studied by combining archaeological evidence with ethnohistoric and contemporary sources. General models of great importance to Andean studies such as vertical complementarity, the question of the commerce in the prehispanic economy, and a structure of dual organization in the Inka administration are examples of models emerging from ethnohistoric sources but with empirical support from archaeological research. Ethnohistorically based models also have their limitations in that they can unduly influence interpretation much in the way that the "tyranny of ethnography"(Wobst 1978)should not necessarily define the range of archaeological possibility and inference. Ethnographic sources are valuable for the evidence of pastoral patterns, the priorities of caravan drivers, and the articulation between mixed and specialized pastoral and agricultural practices. However, modern features including the presence of the cash economy, markets, truckers plying the highways, and various modern job opportunities impact the structure of exchange relationships and caravan transport(Browman 1990;Nielsen 2000).

Ethnographic studies of contemporary llama caravan drivers are focusing, by necessity, on relatively marginalized communities that are sufficiently conservative to continue to herd llamas despite a variety of often more lucrative alternatives (Lecoq 1988;Nielsen 2000). Scholars have noted, however, that caravan drivers enjoyed relatively high status and autonomy in the late prehispanic and early colonial period which contrasts strongly with the economically marginalized modern day caravanero(Murra 1965). Furthermore, herding has become relatively low status in many regions of the contemporary Andes because the economic focus has moved downslope since Spanish contact due to the growth of the coastal economy and the importation of various low altitude crops and livestock. In other words, the prominence of caravan drivers as central economic agents has been greatly diminished in recent centuries, and ethnographically documented interactions with agriculturalists is one circumstance in which this relative shift in power may result in distorted perceptions of prehispanic interaction patterns. The relatively high status accorded to truck drivers and other purveyors of goods and information in contemporary Andean villages was likely to have been ascribed, instead, to the relatively cosmopolitan drivers of llama caravans during prehispanic times.