Kacelnik A, Brito e Abreu F
Department of Zoology, University of Oxford, Oxford, OX1 3PS, U.K.
J Theor Biol. 1998 Sep 21;194(2):289-98. doi: 10.1006/jtbi.1998.0763.
We present a family of models of choice between behavioural alternatives with stochastic outcomes (risky choice) based on the effects of Weber's Law in memory. These models generalise and extend a model of risk sensitive foraging originally proposed by Reboreda & Kacelnik [(1991) Behav. Ecol. 2, 301-308], which yielded qualitative predictions (risk-aversion for amount of food and risk-proneness for delay to food). We now demonstrate how this approach can predict quantitatively the partial preferences between two alternative options with any mean and variance in their outcomes, and the certainty equivalent of an option consisting of any set of probabilistic outcomes. The approach is also relevant to the economics and psychology of risk sensitivity because it predicts risk aversion for any desirable outcome (such as monetary gains) and risk seeking for any undesirable gain (such as monetary losses). Our models are process-based rather than purely normative, and are based on linear expected utility as a function of expected outcomes. They do not account for all observed aspects of risky choice, but their descriptive performance betters that of existing functional models and requires fewer parameters.
我们提出了一系列基于记忆中韦伯定律效应的、在具有随机结果的行为选择之间进行抉择的模型（风险选择）。这些模型推广并扩展了最初由雷博雷达和卡塞尼克[（1991年）《行为生态学》2，301 - 308]提出的风险敏感觅食模型，该模型得出了定性预测（对食物数量的风险厌恶和对获取食物延迟的风险偏好）。我们现在展示这种方法如何能够定量预测两个具有任意均值和方差结果的替代选项之间的部分偏好，以及由任意一组概率性结果组成的选项的确定性等价物。该方法也与风险敏感性的经济学和心理学相关，因为它预测对任何期望结果（如货币收益）的风险厌恶以及对任何不期望收益（如货币损失）的风险寻求。我们的模型基于过程而非纯粹规范性的，并且基于作为期望结果函数的线性期望效用。它们没有考虑风险选择的所有观察到的方面，但它们的描述性能优于现有功能模型，并且所需参数更少。
