Dynamic decision-making in uncertain environments I. The principle of dynamic utility

Journal of Ethology - Tập 31 - Trang 101-105 - 2013
Jin Yoshimura1,2,3, Hiromu Ito1, Donald G. Miller III4, Kei-ichi Tainaka1
1Department of Systems Engineering, Shizuoka University, Hamamatsu, Japan
2Department of Environmental and Forest Biology, College of Environmental Science and Forestry, State University of New York, Syracuse, USA
3Marine Biosystems Research Center, Chiba University, Kamogawa, Japan
4Department of Biological Sciences, California State University, Chico, USA

Tóm tắt

Understanding the dynamics or sequences of animal behavior usually involves the application of either dynamic programming or stochastic control methodologies. A difficulty of dynamic programming lies in interpreting numerical output, whereas even relatively simple models of stochastic control are notoriously difficult to solve. Here we develop the theory of dynamic decision-making under probabilistic conditions and risks, assuming individual growth rates of body size are expressed as a simple stochastic process. From our analyses we then derive the optimization of dynamic utility, in which the utility of weight gain, given the current body size, is a logarithmic function: hence the fitness function of an individual varies depending on its current body size. The dynamic utility function also shows that animals are universally sensitive to risk and display risk-averse behaviors. Our result proves the traditional use of expected utility theory and game theory in behavioral studies is valid only as a static model.

Tài liệu tham khảo

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