时间方向等因素影响跨期决策的实验研究

Experiment on Factors Influencing the Inter-temporal Decision Making

跨期决策中主要存在三个价值不对等现象:时间折扣、符号效应和过去、未来的价值不对等,上述不对等现象涉及到时间距离、时间方向和损益情境三个主要评价维度。本研究旨在通过实验考察时间距离、时间方向和损益情境在跨期决策中的相互作用。通过设置获益(中奖)和损失(罚款)的假想场景,要求被试对不同时间距离、不同时间方向上的决策任务作出判断,根据双曲模型,计算时间折扣率。结果,时间距离影响未来方向决策,而不影响过去方向决策;相同时间距离条件下,未来方向折扣率显著大于过去方向折扣率;损失折扣率大于获益折扣率,得到"反符号效应"。

There are three main aspects of asymmetry among the intertemporal choice, including time discount, sign effect, and temporal value asymmetry. These aspects, furthermore, refer to the three dimensions： temporal orientation, temporal distance and framing effect. In this study, we conducted an experiment to test the interaction of the three dimensions above by employing two kinds of scenario （gain vs. loss） to asked the participants to judge each scenario according to the different temporal distance （1 month vs. 12 months） and orientations （future vs. past） , then calculated the discounting rate of individual participant based on the Hyperbolic Discounting Model. The results showed that the temporal distance has an influence on the ＂future＂ events instead of the ＂past＂ , and the discounting rate of the ＂future＂ was significantly greater than that of the ＂past＂ in terms of the same temporal distance. On the other hand, the discounting rate of the ＂loss＂ was significantly greater than that of ＂gain＂ . Therefore, it proves the reverse sign effect.