Newbold Stephen C, Dockins Chris, Simon Nathalie, Maguire Kelly, Sakib Abdullah Muhammad
Department of Economics, University of Wyoming, Laramie, Wyoming, United States of America.
National Center for Environmental Economics, U.S. Environmental Protection Agency, Washington, D.C., United States of America.
PLoS One. 2025 Jun 13;20(6):e0324630. doi: 10.1371/journal.pone.0324630. eCollection 2025.
We developed and examined the performance of a two-stage random-effects meta-analysis estimator for synthesizing published estimates of the value per statistical life (VSL). The meta-estimation approach accommodates unbalanced panels with one or multiple observations from each independent group of primary estimates, and distinguishes between sampling and non-sampling sources of error, both within and between groups. We used Monte Carlo simulation experiments to test the performance of the meta-estimator on constructed datasets. Simulation results indicate that, when applied to datasets of modest size, the approach performs best when the within-group non-sampling error variances are assumed to be homogeneous among groups. This allows for two levels of non-sampling errors while preserving degrees of freedom and therefore increasing statistical efficiency. Simulation results also show that the estimator compares favorably to several other commonly used meta-analysis estimators, including other two-stage estimators. As a demonstration, we applied the approach to a pre-existing meta-dataset including 113 VSL estimates assembled from 10 revealed preference and 9 stated preference studies conducted in the U.S. and published between 1999 and 2019.
我们开发并检验了一种两阶段随机效应荟萃分析估计量的性能，用于综合已发表的统计生命价值（VSL）估计值。这种荟萃估计方法适用于不平衡面板，每个主要估计的独立组有一个或多个观测值，并区分组内和组间误差的抽样和非抽样来源。我们使用蒙特卡罗模拟实验来测试荟萃估计量在构建数据集上的性能。模拟结果表明，当应用于中等规模的数据集时，若假定组内非抽样误差方差在各组之间是齐性的，该方法表现最佳。这允许存在两个层次的非抽样误差，同时保留自由度，从而提高统计效率。模拟结果还表明，该估计量与其他几种常用的荟萃分析估计量相比具有优势，包括其他两阶段估计量。作为一个示范，我们将该方法应用于一个现有的荟萃数据集，该数据集包括从1999年至2019年在美国进行并发表的10项显示性偏好研究和9项陈述性偏好研究中汇总得到的113个VSL估计值。
