Viki Reyes and her co-authors measure agreement among informants ? as a proxy for knowledge ? through multiple choice questionnaires on plant uses. Their goal is to overcome earlier studies by ?including a large number of observations and using many covariates? to assess the impact of market integration. Based on free lists given by 50 Tsimane participants, they selected 92 plant species and asked informants about their use in building, firewood, food, medicine, canoes and tools. The study incorporated an intensive panel survey with 108 adults in two villages and a comparative cross-sectional survey of 497 households in 59 villages. The analysis uses ordinary least squares regression to elucidate patterns of cultural consensus and competence using demographic, market integration and habitat variables.

There are interesting explorations of:

1. the advantages and limitations of this approach,
2. the use of proxies;
3. and the concept of endogeneity (biases in estimations).

Prepared by: Gary Martin [GJM], Director, The Global Diversity Foundation and Lecturer, Department of Anthropology, University of Kent, July 2006