Stochastic choice, systematic mistakes and preference estimation

Individual choice exhibits "presentation effects" such as default, ordering and round-number effects. Using existing models, presentation effects bias utility estimates, which suggests instability of preferences and obscures behavioral patterns. This paper derives a generalized model of stochastic choice by weakening logit's axiomatic foundation. Weakening the axioms implies that focality of options is choice-relevant, alongside utility, which entails presentation effects. The model is tested on four well-known studies of dictator games exhibiting typical round-number patterns. The generalized logit model captures the choice patterns reliably, substantially better than existing models: it robustly predicts and controls for the round-number effects, thus provides "clean" utility estimates that are stable and predictive across experiments.