Numerical models and structures

This chapter is concerned with numerical systems whose operation is constantly tested against the pragmatic demands of everyday life: indeed their whole rationale is to satisfy these demands. The starting point is the proposition that the economy, society and politics of any defined human population are dynamic systems – although they may be in equilibrium. The totality of any such system may be called its structure, which, conceptually, consists, not so much of all the bits and pieces which would be revealed by any attempt to dismantle it, but of the interactions which take place between them. The investigation of structure in this sense is part of any ethnography – that is the scientific process of establishing the empirical basis of any economic, social or political institution. Such investigation does not, however, answer the questions as to how and why the system works, or is seen to work by those involved in it, which is not necessarily the same thing at all. Answering this latter question is another part of any good ethnography: it is what establishes the cognitive basis of the institutions being studied. The answer to both questions takes the form of a model. In the one case it is ‘the anthropologist's hypothesis about “how the[…]system works”’ (Leach 1964: 8), in the other, it is the local community's understanding of the same question.