Simple Financial Economic Models of Fremont Maize Storage and an Assessment of External Threat

This paper presents a pair of models of the storage of maize. One is directly based on standard financial models of portfolio choice. Rather than optimally balancing a financial portfolio by choosing from a variety of financial instruments, our agents optimize holdings of maize by choosing from a variety of storage locations. Agents face a tradeoff between the effort of transporting maize to high elevation granaries versus the safety they offer from theft. The second model uses a multi-period framework to look at the costs and benefits of building a granary in the first place. We use our models to extract a perceived probability of maize theft by outsiders among the Fremont Indians that lived in Eastern Utah roughly 1000 - 700 years ago. We base our estimates on the caloric content of maize, the caloric cost of transporting it to granaries high above the valley floor where the maize was grown, and the costs of building and maintaining them. Our calculations show that a fairly low level of risk, on the order of 5% to 20%, could easily rationalize the use of cliffside granaries.