Abstract: “Understanding and improving decision-making” is considered to be a major priority for researchers in behavioral decision-making. Investigating framing effects can simultaneously serve both goals. Currently, framing effects are extensively studied and applied in the fields of multi-attribute and risky decision-making, with relatively less attention given to intertemporal and spatial decision-making, despite their common occurrences in real-life scenarios. Given the interchangeable nature of time and space (i.e., distance = time × velocity, where the velocity is a constant), the same decision problem can be described either as a spatial decision problem using spatial framing or as an intertemporal decision problem using temporal framing. The scientific questions addressed in this study are as follows: (1) Whether there exists a phenomenon called the "time-space framing effect" in spatiotemporal decision contexts? Specifically, this effect refers to changes in people's decision preferences when the same decision problem is described using either a time or space frame. (2) If this effect indeed exists, what are its underlying psychological mechanisms? (3) Can the time-space framing effect be used to nudge people’s decision-making behavior in real life? To address the proposed question, this study will examine the phenomenon of the time-space framing effect (Study 1), unravel its psychological mechanisms (Studies 2 and 3), and ascertain its practical implications for nudging behavior (Study 4) by employing multiple methods, such as cognitive-behavioral approaches, eye-tracking techniques, and field experiments.
The theoretical and practical implications of this study are primarily reflected in three aspects: Firstly, the approach to frame manipulation in this study differs from that of previous studies. Previous studies typically focused on manipulating frames within the same dimension, such as the attribute framing effect in the multi-attribute decision-making and the classic gain-loss framing effect in the risky decision-making. These studies usually involve changes in the positivity or negativity of attributes or outcomes within the same dimension, which can be categorized as a "qualitative" manipulation within the domain. In the domains of intertemporal and spatial decision-making, frame manipulation within the monetary/time/space unit effects entails altering numerical units within the same outcome dimension or the time/space dimension, which can be categorized as a "quantitative" manipulation within the domain. However, the manipulation of the time-space frames in this study spans across the domains of intertemporal and spatial decisions (i.e., frame manipulation within different dimensions), thus representing an exploration of a novel, cross-domain "qualitative" framing manipulation.
Secondly, investigating the time-space framing effect and its mechanisms provides a new perspective and paradigm for understanding intertemporal and spatial decisions. This study integrates theories concerning the convertible relationship between time and space, psychological distance theory, construal-level theory, and theories concerning two broad classes of decision models regarding intertemporal and spatial decisions (i.e., the utility comparison models and the attribute-comparison models). It attempts to propose a theoretical hypothesis model that can simultaneously integrate the "binary choice" and the "single option" decision contexts to explain the mechanisms underlying the time-space framing effect. Furthermore, multiple research methods, including static behavioral outcome tests and dynamic eye-tracking techniques, are employed to examine the decision-making processes when people face spatiotemporal decision contexts and the underlying reasons leading to changes in decision preferences.
Finally, while previous research has been limited to investigating the spatiotemporal framing effect in laboratory or virtual contexts, this study will conduct a series of field quasi-experiments to provide tangible evidence and relevant recommendations for examining the nudging effects of the time-space framing effect in real-world contexts.
In sum, the findings of this study are expected to provide a new paradigm and theoretical contribution for understanding intertemporal and spatial decision-making, while offering some psychological insights to nudge individuals and organizations toward making more judicious decisions.

Key words: intertemporal choice, spatial choice, framing effect, psychological mechanism, nudge