Narrow Bracketing and Dominated Choices
证明，任何非恒定绝对风险厌恶的决策者若采用窄框定（单独评估决策），都会在某些简单二元选择中做出一阶随机占优的联合选择。实验显示28%的参与者选择了占优组合，且偏好符合前景理论。
We show that any decision maker who “narrowly brackets” (evaluates decisions separately) and does not have constant-absolute-risk-averse preferences will make a first-order stochastically dominated combined choice in some simple pair of independent binary decisions. We also characterize the preference-contingent monetary cost from this mistake. Empirically, in a real-stakes laboratory experiment that replicates Tversky and Kahneman's (1981) experiment, 28 percent of participants choose dominated combinations. In a representative survey eliciting hypothetical large-stakes choices, higher proportions do so. Violation rates vary little with personal characteristics. Average preferences are prospect-theoretic, with an estimated 89 percent of people bracketing narrowly.