Here we argued that publishing everything is superior to selective publishing. More generally, in line with what is considered as best practice in meta-analysis, we recommend researchers to include both published and unpublished papers [26]. Meta-analyses in W&H's selective publishing approach only consider (published) studies with results that deviate significantly from earlier evidence, and disregard all other (unpublished) studies. A relevant question is what happens to the accuracy of the meta-analytic estimate in selective publishing if a random selection of unpublished studies is included in the meta-analysis in addition to the ones that are published. Assuming all studies estimate the same underlying population effect, the accuracy of the estimate increases, since more unbiased information is incorporated in the analysis. Hence, even selective publishing benefits from including unpublished studies. Statistically speaking, more information is always better as long as the information is unbiased. In any case, methods of meta-analysis are needed that yield accurate effect size estimates even under the most extreme scenarios of publication bias [27].
