Abstract: In everyday life, decisions that require weighing outcomes at different points in time are referred to as intertemporal choices. Intertemporal choices include single-dated and multiple-dated outcomes. The former limits the intertemporal choice task to a trade-off between the outcomes of two single dates while the latter involves trade-offs of two or more outcomes at multiple points in time. At present, compared to the single-dated intertemporal choice, where research is abundant and the understanding of the psychological mechanism of which is increasingly consistent, research on multiple-dated outcomes in intertemporal choice is relatively weak. Increasingly, research shows that multi-dated intertemporal choice and single-dated intertemporal choice have different psychological mechanisms and produce different decision effects. Thus, what are the decision effects in multiple-dated intertemporal choices? What are the characteristics of these decision effects? This paper discusses the decision effect and its psychological mechanism in the multiple-dated intertemporal choice from two-dated outcomes and sequential outcomes.
The intertemporal choice task of the two-dated outcome is composed of the added outcome in the options of paired single-dated intertemporal choice tasks. Depending on the nature (zero, non-zero) and location (before, during, and after the original option) of the added outcome, many decision effects have been found in the intertemporal choice of the two-dated outcome, including the hidden zero effect, symbolic effect, extra-dated money effect, and front-end amount effect. The sequential outcome of intertemporal choice is a sequence result (such as increasing, decreasing, and constant) composed of two or more time point results. Studies have shown that in the face of intertemporal choice of sequence results, individuals prefer increasing sequences to decreasing sequences with the greatest utility, which is called the sequence effect.
In view of the above decision effect, researchers have proposed different theoretical models to explain it. Mainstream theories mainly include trade-off and sequence models. The trade-off model deviates from the assumption of a time discount, and the trade-off model of the single-dated intertemporal choice domain was developed to adapt to the multi-dated intertemporal choice scenario. The sequential model is based on the assumption of time discounting. First, it is aimed mainly at the intertemporal choice of sequential outcomes, and new parameters are introduced on the basis of the discount model to construct the model to explain decision effects, such as the sequence effect. Restricted by the theory itself, we believe that the dimensional-based trade-off model is more suitable for explaining many decision effects in the intertemporal choice of two-dated outcomes, while the sequence model is better suited to explain the sequence effects in the sequential intertemporal choice.
At present, research on decision effect in intertemporal choice of multi-dated outcomes is still relatively general and the process mechanism has not yet been explored. To expand on the mechanism explanation of decision effect in multi-dated intertemporal choice, for example, focusing on the causes of people's decision effect, basic psychological characteristics (such as decision motivation factors) may be extracted to explain the decision effect in multi-dated intertemporal choice. In addition, in order to more accurately describe and explain the decision effect and the psychological mechanism of multi-dated intertemporal choice, subsequent research should strengthen the discussion on the process mechanisms. In particular, new process tracing methods, such as mouse-tracing, can provide a data-rich real-time window, which would be helpful for exploring the dynamic decision-making process mechanism of decision effect in multi-dated intertemporal choice.

Key words: intertemporal choice, single dated outcome, multiple dated outcomes, sequential model, trade-off model