Primary Outcomes (explanation)
Our principal measure of economic rationality is choice consistency, defined as a binary variable equal to 1 if a participant’s choices satisfy the Generalized Axiom of Revealed Preference (GARP), a necessary and sufficient condition for consistency with preference maximization (Afriat, 1967; Varian, 1982). Guided by our theoretical framework, we pre-register the following hypothesis:
Hypothesis 1: Sequential elimination improves choice consistency relative to the direct procedure among individuals with cognitive limitations.
We test this hypothesis among low-IQ participants (those scoring at or below the sample median), who serve as a proxy for individuals with cognitive limitations.
As pre-registered robustness checks, we employ alternative measures of economic rationality: the number of GARP violations, the Houtman–Maks Index (HMI; Houtman and Maks, 1985), and stricter variants of these measures that additionally impose first-order stochastic dominance (FSD). The number of GARP violations quantifies departures from rationality. The HMI is defined as the minimum number of choices that must be removed to achieve consistency, with removed choices typically interpreted as mistakes. The FSD-based variants impose a stricter normative benchmark for decision-making under risk. These measures offer complementary assessments of sequential elimination, varying in stringency and granularity. The Supplementary Materials report the minimum detectable effects for all measures, providing a complete account of design sensitivity.
References:
Afriat, Sidney N. 1967. “The Construction of Utility Functions from Expenditure Data.” International Economic Review 8 (1): 67–77.
Houtman, Martijn, and Julian Maks. 1985. “Determining All Maximal Data Subsets Consistent with Revealed Preference.” Kwantitatieve Methoden 19 (1): 89–104.
Varian, Hal R. 1982. “The Nonparametric Approach to Demand Analysis.” Econometrica 50 (4): 945–973.