We present a novel descriptive model of choice that achieves an efficient representation anchored to how the brain represents value. An individual's behavior is fully described by two primitives: an individual's "reward expectation'' and a free parameter we call "predisposition''. We demonstrate...

Prospect theory, widely used descriptively for decisions under both risk and certainty, presumes concave utility over “gains” and convex utility over “losses”; a pattern widely seen in lottery tasks. Although such gain-loss asymmetry is also widely used to model riskless choices, limited...