Browsing by Subject "bias"

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    Biased experts, majority rule, and the optimal composition of committee
    (Games and Economic Behavior, 2021-05-01) Name Correa, AJ; Yildirim, H
    An uninformed principal appoints a committee of experts to vote on a multi-attribute alternative, such as an interdisciplinary project. Each expert evaluates one attribute and is biased toward it (specialty bias). The principal values all attributes equally but has a status quo bias, reflecting the organizational cost of a change. We study whether the principal would compose the committee of more or less specialty-biased experts. We show that her optimal composition is nonmonotonic in the majority rule, with the most biased experts appointed under intermediate rules. We then show that the principal would be less concerned about the committee composition if its members can be uninformed, as they induce the informed to vote less strategically. Surprisingly, although uninformed members lower the quality of the committee's decision, the principal may prefer to have some when its composition is suboptimal, and the majority rule is sufficiently extreme, such as the unanimity.
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    Interim analysis of binary outcome data in clinical trials: a comparison of five estimators.
    (Journal of biopharmaceutical statistics, 2019-01) Lu, Qing Shu; Chow, Shein-Chung; Tse, Siu-Keung
    In clinical trials, where the outcome of interest is the occurrence of an event over a fixed time period, estimation of the event proportion at interim analysis can form a basis for decision-making such as early trial termination, sample size re-estimation, and/or dropping inferior treatment arms. In addition to derivation of mean squared error under an exponential time-to-event distribution, we performed a simulation study to examine the performance of five estimators of the event proportion when time to the event is assessable. The simulation results showed advantages of the Kaplan-Meier estimator over others in terms of robustness, and the bias and variability of the event proportion estimate. An example was given to illustrate how the estimators affect dropping treatment arms in a multi-arm multi-stage adaptive trial. We recommended the use of the Kaplan-Meier estimator and discourage the use of other estimators that discard the inherent time-to-event information.