Violations of the assumptions of complete information [CI] and independence of irrelevant alternatives (IIA) in discrete-choice experiment (DCE) data imply sensitivity of preference estimates to the decision context and the alternatives evaluated. There is a paucity of evidence on how these two assumptions affect health-preference results and whether the usual specifications of random-parameters logit models are sufficient to address these violations. We assessed the appropriateness of these assumptions in a DCE valuating interventions to prevent long-term health problems that could be identified through whole genome sequencing. A DCE survey was administered to members of a nationally representative consumer panel to elicit their preferences for options to reduce the risk of health problems. The treatment options presented (surgery, medication, and watchful waiting) and the context for the decisions elicited (severity and likelihood of the health problem) were varied experimentally to evaluate the sensitivity of preference results to such changes. We find evidence of IIA violations as the options presented to prevent health changed. Our results also are consistent with the expectation that additional substitutes decrease the monetized value of alternatives. We also find some evidence that the decision context can moderate such effects, which constitutes a new finding.

中文翻译：

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健康干预的陈述偏好值中的不完整信息和不相关属性

离散选择实验 (DCE) 数据中对完整信息 [CI] 和无关替代方案 (IIA) 独立性假设的违反意味着偏好估计对决策上下文和评估的替代方案的敏感性。关于这两个假设如何影响健康偏好结果以及随机参数 logit 模型的通常规范是否足以解决这些违规问题，缺乏证据。我们在 DCE 评估干预措施中评估了这些假设的适当性，以防止可以通过全基因组测序识别的长期健康问题。对具有全国代表性的消费者小组成员进行了一项 DCE 调查，以了解他们对降低健康问题风险的选择的偏好。提出的治疗方案（手术、药物、和观察等待）和引发的决定的背景（健康问题的严重性和可能性）在实验上有所不同，以评估偏好结果对这些变化的敏感性。我们发现了违反 IIA 的证据，因为为防止健康而提出的选项发生了变化。我们的结果也与额外替代品会降低替代品的货币化价值的预期一致。我们还发现了一些证据表明决策上下文可以缓和这种影响，这构成了一个新的发现。我们的结果也与额外替代品会降低替代品的货币化价值的预期一致。我们还发现了一些证据表明决策上下文可以缓和这种影响，这构成了一个新的发现。我们的结果也与额外替代品会降低替代品的货币化价值的预期一致。我们还发现了一些证据表明决策上下文可以缓和这种影响，这构成了一个新的发现。