In the political economy of the Quito region we have seen some classically Inca institutions interlaced with others, markedly different, of local origin. They can be separated analytically, but in concrete reality they did not exist in isolation from each other. They existed in a problematic, and apparently unstable, state of interaction. Relations between Tawantinsuyu and economies of fundamentally foreign constitution have, in the last few years, become the object of intensive case study in the distinguished works of Maria Rostworowski de Díez Canseco (1970, 1975) and of bold generalizations in a synthesis by Alfredo Torero (1974).

The very fact that we find these systems in interaction, and even in part functionally interdependent, makes it hard to reconstruct the historical process of which the state of affairs around Quito formed one moment. The Quito case does not present any single aboriginal society in a state of pristine autonomy, but always constrained and modified by Inca pressures. And although we know that the Inca state in its northern variant did not show all the traits typical of the Inca heartland, we do not know whether to attribute this to a “Quito-ization” of the regime under aboriginal pressures, or to an incipient phase of Inca governance as opposed to a mature one.

Given the limited time depth of ethnohistorical techniques, these problems might best be solved by employing Eggan's “method of controlled comparisons” (Eggan 1954).