Market economy and the loss of folk knowledge of plant uses : estimates from the Tsimane' of the Bolivian Amazon - Reyes-García, Victoria (Brandeis University. Heller School for Social Policy and Management) ; Vadez, Vincent (Brandeis University. Heller School for Social Policy and Management) ; Byron, Elizabeth (International Food Policy Research Institute) ; Apaza, Lilian (Proteccin del Medio Ambiente Tarija) ; Leonard, William R. (Northwestern University. Department of Anthropology) ; Pérez, Eddy (Fundación para el Desarrollo de la Ecología. Estación Biológica Tunquini) ; Wilkie, David (Wildlife Conservation Society)