Green L, Myerson J, McFadden E
Department of Psychology, Washington University, St. Louis, MO 63130, USA.
Mem Cognit. 1997 Sep;25(5):715-23. doi: 10.3758/bf03211314.
The present, subjective value of a delayed reward is a decreasing function of the duration of the delay. This phenomenon is termed temporal discounting. To determine whether the amount of the reward influences the rate of temporal discounting, we had subjects choose between immediate and delayed hypothetical rewards of different amounts ($100, $2,000, $25,000, and $100,000 delayed rewards). As predicted by psychological models of the choice process, hyperbolic functions described the decrease in the subjective value of the delayed reward as the time until its receipt was increased (R2s from .86 to .99). Moreover, hyperbolic functions consistently provided more accurate descriptions of the data than did exponential functions predicted by an economic model of discounted utility. Rate of discounting decreased in a negatively accelerated fashion as the amount of the delayed reward increased, leveling off by approximately $25,000. These findings are interpreted in the context of different psychological models of choice, and implications for procedures to enhance self-control are discussed.
延迟奖励的当前主观价值是延迟持续时间的递减函数。这种现象被称为时间贴现。为了确定奖励金额是否会影响时间贴现率，我们让受试者在即时奖励和不同金额的延迟假设奖励（100美元、2000美元、25000美元和100000美元的延迟奖励）之间进行选择。正如选择过程的心理模型所预测的那样，双曲线函数描述了随着延迟奖励接收时间的增加，其主观价值的下降（决定系数从0.86到0.99）。此外，双曲线函数始终比贴现效用经济模型预测的指数函数更准确地描述数据。随着延迟奖励金额的增加，贴现率以负加速的方式下降，在约25000美元时趋于平稳。这些发现是在不同的选择心理模型的背景下进行解释的，并讨论了对增强自我控制程序的影响。
