Taboo trade-off aversion in choice behaviors: a discrete choice model and application to health-related decisions

Respondents: 708 citizens Choice tasks: 14 per respondent Total observations: 9,912 File: healthinsurance_dce.csv Dataset 2: Taboo trade-offs in organ transplantation policy decisions (OT-DCE) The OT-DCE aimed to understand public preferences regarding increases in health insurance premiums to fund a new technique for refurbishing lower-quality organs to make them suitable for transplantation. By refurbishing otherwise unusable organs, additional lives could be saved.

Respondents: 691 citizens Choice tasks: 10 per respondent (dual-response format) Total observations: 6,910 File: organtransplantation_dce.csv Both datasets were used for the publication “Taboo trade-off aversion: a discrete choice model and application to health-related decisions.” in the Social Science & Medicine journal (doi.org/10.1016/j.socscimed.2025.118606) To replicate the analyses reported in the publication, please refer to the project’s GitHub repository: github.com/nvrsmeele/ttoamodel Ethical approval for both DCEs was obtained from the Research Ethics Review Committee, Erasmus School of Health Policy & Management (ETH2223-0324).

This research was supported by a seed grant from the Erasmus Initiative – Smarter Choices for Better Health (SCBH), awarded to the first (corresponding) author.

Abstract

Objectives: Taboo trade-offs can explain some of the (moral) difficulties in healthcare decision-making. The moral psychology literature suggests that individuals are averse to making trade-offs between attributes belonging to different values, such as (sacred) human lives versus (secular) money. We demonstrate and empirically test a discrete choice model designed to capture Taboo Trade-off Aversion (TTOA) behaviors in the healthcare domain.

Methods

The linear-additive Random Utility Maximization (RUM) model is extended to capture TTOA behaviors by including penalties for taboo trade-offs. Using two Discrete Choice Experiments (DCEs) focusing on taboo trade-offs in public health policies, we empirically compare conventional linear-additive RUM models with TTOA models to explore differences in model and behavioral results. Results: We observe TTOA in both DCEs.

In one DCE, the TTOA model separates TTOA effects from attribute-related parameters, showing inflated parameters in conventional RUM models when TTOA behavior is present. This discrepancy affected Willingness-To-Pay (WTP) estimates, with WTP to save an incremental patient life approximately 3.5 times higher in conventional RUM models compared to the TTOA models. The presence and magnitude of TTOA varied considerably across respondents.

Latent Class (LC) models reveal that some respondent groups perceive trade-offs as taboo significantly, while others do not. Conclusions: Accounting for TTOA in RUM models may lead to more accurate behavioral information when choice behaviors are affected by taboo trade-offs. Researchers and policymakers can use TTOA models to obtain a more nuanced understanding of public acceptability in morally salient policy decisions – ultimately helping to navigate, rather than avoid, taboo trade-offs.