Magnitude, Time, and Risk Differ Similarly between Joint and Single Evaluations

Arguably, all choice options involve three basic attributes: magnitude (outcome size), time (of occurrence), and probability (of occurrence) and are evaluated in one of two basic evaluation modes: JE (joint evaluation, involving comparison of multiple options) and SE (single evaluation, without comparison). This research explores how reactions to the three basic attributes (and their associated functions—utility, time discounting, and probability weighting) vary between the two basic evaluation modes. Nine studies, tapping diverse contexts, yield two general results: first, for all these attributes, people are more sensitive to variations near endpoints (zero magnitude, no delay, and 0% or 100% probability) than in other regions, and this differential sensitivity is more pronounced in SE than in JE. Second, when faced with options involving a trade-off between magnitude and time (delay) or between magnitude and probability (risk), people are both more delay averse and more risk averse in SE than in JE.