Hunting, gathering, and fishing economies can change from one type of foraging economic system to another, and it is as important to understand these dynamic aspects of the system as it is to know the static elements of the system at a single point in time. Unfortunately, the evidence for such systemic transformations of these economies is skimpy and, as a result, this type of systemic transformation has received relatively little attention in the ethnographic literature. Foraging systems can also change into agricultural systems. The evidence for this transition – the “neolithic revolution” – is more abundant and has engendered a vast literature, but I am uncomfortable with it.

When discussing the transition from foraging to farming, most archaeologists and anthropologists adopt a bottom-up approach and usually rest their argument on a small number of cases, generalizing from these results to all transitions in other places. Such a procedure rests on the dubious assumption that the transition proceeded in a similar fashion all over the world. By way of contrast, economists have adopted a top-down approach. In previous years, they usually started from one or more of four general propositions about the causes of the transition (Weisdorf: 2003a): that it was a result of diminishing returns in foraging as the population increased; that it was a result of a general decrease in foraging productivity arising from a change in climate or an extinction of the plants and animals being foraged; that it was a result of a rise in the productivity of agriculture due to the invention or borrowing of more productive techniques in farming; or that it was a result of a shift in preferences for nonfood items that could be obtained only by exchanging agricultural goods.