Cox David J, Dallery Jesse
University of Florida, Department of Psychology, United States.
Behav Processes. 2018 Aug;153:84-91. doi: 10.1016/j.beproc.2018.05.012. Epub 2018 May 18.
The rates that an outcome (e.g., money) loses value as delay increases or probability decreases are called delay and probability discounting, respectively. Discounting is typically studied by asking participants to make choices between two options that vary in amount and delay (e.g., $50 now vs. $100 in 3 months) or probability (e.g., 100% chance of $50 vs. 60% chance of $100). Little is known about how more complex options affect discounting. We asked participants (N = 56) to choose between two options that each resulted in two outcomes (e.g., getting $50 now and losing $1000 in 6 months vs. getting $100 in 3 months and losing $500 now). The second outcome varied across a range of delays and probabilities. Results indicated the probability of the second outcome had a greater influence on rates of discounting compared to the delay to the second outcome. Increasing the probability of the loss decreased rates of discounting the first outcome (i.e., increased preference for the larger-later alternative). Finally, a multiplicative model best described discounting of two, delayed-and-probabilistic outcomes. This suggests the value of two outcomes interact to influence rates of discounting.
随着延迟增加或概率降低，结果（如金钱）的价值损失率分别称为延迟折扣和概率折扣。通常通过要求参与者在两个金额和延迟（如现在的50美元与3个月后的100美元）或概率（如50美元的100%可能性与100美元的60%可能性）不同的选项之间进行选择来研究折扣。对于更复杂的选项如何影响折扣知之甚少。我们要求参与者（N = 56）在两个各产生两个结果的选项之间进行选择（如现在得到50美元且6个月后损失1000美元与3个月后得到100美元且现在损失500美元）。第二个结果在一系列延迟和概率范围内变化。结果表明，与第二个结果的延迟相比，第二个结果的概率对折扣率的影响更大。增加损失的概率会降低对第一个结果的折扣率（即增加对更大-更晚选项的偏好）。最后，一个乘法模型最能描述两个延迟和概率结果的折扣情况。这表明两个结果的价值相互作用以影响折扣率。
