Attema, ArthurBleichrodt, HanL’Haridon, OlivierLipman, Stefan A.2023-11-262023-11-261618-7598http://hdl.handle.net/1885/307433Quality-Adjusted Life-Years (QALYs) are typically derived from individual preferences over health episodes. This paper reports the frst experimental investigation into the efects of collective decision making on health valuations, using both time trade-of (TTO) and standard gamble (SG) tasks. We investigated collective decision making in dyads, by means of a mixed-subjects design where we control for learning efects. Our data suggest that collective decision making has little efect on decision quality, as no efects were observed on decision consistency and monotonicity for both methods. Furthermore, QALY weights remained similar between individual and collective decisions, and the typical diference in elicited weights between TTO and SG was not afected. These fndings suggest that consulting with others has little efect on health state valuation, although learning may have. Additionally, our fndings add to the literature of the efect of collective decision making, suggesting that no such efect occurs for TTO and SG.application/pdfen-AU© The Author(s) 2020https://creativecommons.org/licenses/by/4.0/Collective decision makingHealth state valuationStandard gambleTime trade-off202010.1007/s10198-019-01155-x2022-08-14Creative Commons Attribution 4.0 International License