WHY HUNTER-GATHERERS WORK - AN ANCIENT VERSION OF THE PROBLEM OF PUBLIC-GOODS

People who hunt and gather for a living share some resources more wide ly than others. A favored hypothesis to explain the differential shari ng is that giving up portions of large, unpredictable resources obliga tes others to return shares of them later, reducing everyone's varianc e in consumption. I show that this insurance argument is not empirical ly supported for !Kung, Ache, and Hadza foragers. An alternative hypot hesis is that the cost of not sharing these resources is too high to p ay. If exclusion costs are high, then these resources are like public goods. If so, why does anyone provide them? I briefly review treatment s of the problem of public goods by economists and use a simple model to show why self-interested actors will rarely find the consumption va lue they place on collective goods sufficient reason to supply them. T he model underlines the obvious corollary that individuals get more to consume if others provide collective goods. This is a reason to prefe r neighbors and associates who are suppliers. Such a preference may it self be a benefit worth seeking. I construct another simple model to e xplore this. Taken together the models suggest two competing foraging goals: feeding one's family and gaining social benefits instead. This highlights conflicts of economic interest among family members. It is a direct challenge to influential scenarios of human evolution built o n the assumption that men are primarily paternal investors who hunt to support their spouses and offspring.