Many hands make hard work, or why agriculture is not a puzzle

The shift from hunting and gathering to agriculture, some 10,000 years ago, triggered the first demographic explosion in history. Along with population, working time increased, while food consumption remained at the subsistence level. For that reason, most anthropologists regard the adoption of agriculture as an economical puzzle. I show, using a neoclassical economic model, that there is nothing puzzling about the adoption of agriculture. Agriculture brings four technological changes: an increase in total factor productivity, a stabilization of total factor productivity, less interference of children on production, and the possibility of food storage. In my model, each of those changes induces free, rational and self-interested hunter-gatherers to adopt agriculture. As a result, working time increases while consumption remains at the subsistence level, and population begins to grow until diminishing returns to labor bring it to a halt. Welfare, which depends on consumption, leisure, and fertility, rises at first; but after a few generations it falls below its initial level. Still, the adoption of agriculture is irreversible. The latter generations choose to remain farmers because, at their current levels of population, reverting to hunting and gathering would reduce their welfare.