Original Paper

Theoretical Ecology

, Volume 6, Issue 2, pp 173-187

First online:

Reciprocal insurance among Kenyan pastoralists

  • Avinash K. DixitAffiliated withDepartment of Economics, Princeton University
  • , Simon A. LevinAffiliated withDepartment of Ecology and Evolutionary Biology, Princeton University Email author 
  • , Daniel I. RubensteinAffiliated withDepartment of Ecology and Evolutionary Biology, Princeton University

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In large areas of low and locally variable rainfall in East Africa, pastoralism is the only viable activity, and cattle are at risk of reduced milk output and even death in dry periods. The herders were nomadic, but following the Kenyan government’s scheme of giving titles to group ranches, they are evolving reciprocity arrangements where a group suffering a dry period can send some of its cattle to graze on lands of another group that has better weather. We model such institutions using a repeated game framework. As these contracts are informal, we characterize schemes that are optimal subject to a self-enforcement or dynamic incentive compatibility condition. Where the actual arrangements differ from the predicted optima, we discuss possible reasons for the discrepancy and suggest avenues for further research.


Kenya Pastoralism Variable rainfall Insurance Self-enforcement