Loss Aversion Is a State, Not Just a Trait
Preregistered Model-Free Evidence from the Field
Yasuhiro Kawakami (Pensata, Inc.) · Ryosuke Fujitani (Hitotsubashi University ICS)
Posted September 30, 2026 · DOI: 10.2139/ssrn.7544500 · Preregistered on OSF (n2mw9)
Why it matters for lenders
Defaults happen under stress, not in calm conditions. This study shows that a risk profile measured once, in the normal state, misses nearly half of the people who become most loss-averse when conditions turn. The BYLAS Engine measures both states in one short session.
Key findings
- Preregistered field experiment with 143 employees of a major Japanese financial group, each measured under a normal frame and then a crisis frame in a single session.
- Loss aversion rose by about 25% under the crisis frame; roughly 90% of participants moved in the same direction.
- Of the participants most loss-averse under stress, 46% could not be identified from their normal-state measurement alone.
- The shift is visible in raw choices, without relying on any estimation model: when offered strictly better odds under the crisis frame, participation fell instead of rising, while a control pair did not move.
- Every reported figure reproduces from an analysis archive frozen under SHA-256 hashes.
Companion to “Beyond FICO” (SSRN, August 2026): this paper provides the field evidence for the two-state measurement framework introduced there.
Abstract
Is loss aversion a trait, or a state? We report a preregistered test: Japanese financial-group employees completed a two-state task (Kawakami and Fujitani, 2026) in one sitting, under a normal and then a crisis frame. Because selected stress items offer strictly better odds, a monotone choice model with unchanged preferences and reference points and no position effects predicts nondecreasing expected participation. It fell, significantly; a matched control pair did not. Loss aversion rises under stress. Three of four registered hypotheses are supported; the attribute bound is falsified for probability weighting alone. Normal-state rank predicts stress-state rank only in part, so single-state measurement misses a state component that the attribute set does not reach.
Keywords: loss aversion, prospect theory, state-dependent preferences, risk preference stability, preregistration, field experiment · JEL: C93, D81, D91, G41