Introduction
Decision-making under conditions of risk and uncertainty is a central concern in behavioral science, particularly during public health crises. This study examines how framing and contextual scale influence individual choices in life-or-death scenarios, drawing on Prospect Theory. Specifically, it compares decision behavior in a hypothetical setting—the Asian Disease Problem (Tversky & Kahneman, 1981)—with responses in a real-world context, the COVID-19 pandemic.


Purpose
The research aims to evaluate (1) the effect of gain versus loss framing on risk preferences and (2) the influence of varying population sizes on choice behavior, thereby testing the principle of diminishing sensitivity.


Method
A quantitative, between-subjects online experiment was conducted with 371 university students. Participants were exposed to ten randomized scenarios involving escalating population sizes (600 to 6,000,000) and framed either positively or negatively. Scenarios were embedded in both a hypothetical disease context and a COVID-19 setting. Statistical analyses were performed using chi-square tests of independence and goodness-of-fit.


Results
Framing had a statistically significant effect on decision outcomes. Participants demonstrated risk-averse behavior under gain framing and risk-seeking behavior under loss framing, aligning with the predictions of Prospect Theory. In contrast, population size did not significantly influence decision behavior, providing no empirical support for diminishing sensitivity. The magnitude of the framing effect was greater in the hypothetical context than in the COVID-19 scenarios.


Conclusions
The findings underscore the robustness of framing effects in crisis-related decision-making, while calling into question the relevance of scale-based sensitivity under conditions of high emotional and cognitive load. The study contributes to the empirical foundation of Prospect Theory and offers practical implications for the design of risk communication strategies in public health contexts.