Saturday, September 30, 2006

Pygmies

In Chapter 2 of The Rise and Fall of Nations: Economic Growth, Stagflation an Social Rigidities, Mancur Olson goes into great depth on what makes a strong theory. He states that a theory that explains broad phenomena is better than one that can only explain very narrow phenomena. As an example he sights Darwin’s theory of evolution. Darwin’s theory is strong because it explains the evolution of all life and not just that of mosquitoes. Olson clearly means for his theory on the nature of groups to explain broad phenomena. So, I thought I would put it to the test on a small group of pygmies living in the African rainforest.

In my anthropology class last semester we read a book entitled, The Forest People. It was written by an anthropologist named Colin Turnbull that lived and worked with the BaMbuti for several years. The BaMbuti live in small band level groups of about 30-50 people throughout the African rainforest. They are nomadic hunter-gatherers; their primary economy is net hunting (and by “economy” I mean a way to make a living – in this case food). Net hunting is among the earliest economies and is unique in that all members of a society take part. The men from each nuclear family set up the nets to form a large, continuous half circle in a particular area of forest. The women and children form a line a ways off and then start shouting and beating the underbrush with sticks to drive the animals in the direction of the nets. Once caught the animals are quickly dispatched, taken back to the temporary village and butchered. The meat is distributed among all of the families regardless of whose net actually caught the animals.

The BaMbuti live in extended family groups. One man’s family was too small to survive on its own and so had attached itself to the group that Turnbull was studying. One day Cephu decided to secretly set up his net in front of the other nets. This was not very efficient. Cephu was able to catch some animals, but the position of his net deflected most of the animals away from the other nets. When the villagers returned home after a disappointing day they found Cephu trying to hide his spoils.

By setting up his net in front of the others Cephu wanted to enlarge his “piece of pie”. He didn’t want to be limited to what was doled out after the collective hunt. In so doing he effectively made the pie smaller for everyone else. Olson would say that Cephu’s decision was logical so long as the cost of the action did not exceed the inverse of the fraction of the group represented by Cephu’s family. Turnbull did not include specific population data so I can’t say for certain that Cephu’s decision was logical according to Olson. However, empirically it seems his decision was not logical. Once the group realized what Cephu had done they confiscated his meat and redistributed it to the rest of the group leaving Cephu’s family without food for the night. (Perhaps if he had not been caught then his decision would have seemed more logical.)

The BaMbuti live in small groups and like any group they have to deal with the problem of free-riding. They offer a collective benefit in the form of meat from group net hunting. To prevent free-riding and other socially unacceptable behaviors (there was a very interesting part involving incest) the BaMbuti have strong negative incentives. The punishment for the gravest of crimes is banishment. For the BaMbuti banishment is death. A lone person or a lone family cannot hope to survive on their own. The threat of banishment helps keep the group together and ensure that everyone does their part.

1 comment:

Larry Eubanks said...

I'm not sure you actually directly said whether or not you thought the example you offer fits with Olson's theorizing or not? Perhaps so, since you refer to having to face the free rider problem. In some respects, your illustration reminds me of the typical story of why cartels don't stay together too long, at least not without the ability to use coercion or to punish cheaters.