Meta-analysis selection bias in marketing research

The tendency of meta-analytic authors to select particular studies is called selection bias. Selection bias can affect the strength of the meta-analytic estimate and the attention that scholars devote to the results. This research is, in effect, a meta-analysis of the effect sizes reported or calculated from 94 meta-analysis studies of various topics in marketing research. The analysis reveals that estimates depend on the publication status of the included studies. The greater the percentage of studies that were published in academic journals vs. non-published studies, the greater is the size of the meta-effects, and the more published studies from leading journals the meta-analysis includes, the stronger the effect size. The meta-analytic effect size is a mediator for the influence of both the ratio of unpublished studies and the ratio of studies from leading journals on the probability of a meta-analysis to be published in a leading journal, which increases the number of citations to a meta-analysis. The findings of this study have several implications for meta-analysts, editors, reviewers and the marketing community on how to conduct and read current and future meta-analysis in marketing research.