Journal article
Understanding Power Anomalies in Mediation Analysis
Psychometrika, Vol.83(2), pp.387-406
06/2018
DOI: 10.1007/s11336-017-9598-1
PMID: 29181805
Abstract
Previous studies have found some puzzling power anomalies related to testing the indirect effect of a mediator. The power for the indirect effect stagnates and even declines as the size of the indirect effect increases. Furthermore, the power for the indirect effect can be much higher than the power for the total effect in a model where there is no direct effect and therefore the indirect effect is of the same magnitude as the total effect. In the presence of direct effect, the power for the indirect effect is often much higher than the power for the direct effect even when these two effects are of the same magnitude. In this study, the limiting distributions of related statistics and their non-centralities are derived. Computer simulations are conducted to demonstrate their validity. These theoretical results are used to explain the observed anomalies.
Details
- Title: Subtitle
- Understanding Power Anomalies in Mediation Analysis
- Creators
- Kai Wang - Department of Biostatistics, College of Public Health, The University of Iowa, Iowa City, IA, 52242, USA. kai-wang@uiowa.edu
- Resource Type
- Journal article
- Publication Details
- Psychometrika, Vol.83(2), pp.387-406
- DOI
- 10.1007/s11336-017-9598-1
- PMID
- 29181805
- ISSN
- 0033-3123
- eISSN
- 1860-0980
- Grant note
- P30 ES005605 / NIEHS NIH HHS
- Language
- English
- Date published
- 06/2018
- Academic Unit
- Biostatistics
- Record Identifier
- 9984214787102771
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