Meta-analyses overestimate effect sizes because null results go unpublished.

Evidence

Researchers may be reluctant to send in studies with modest or countertheory findings. And journals may publish studies with large effects and reject studies with small or no effects. Thus, reviews may systematically overestimate effect sizes, as they rely heavily on published work. — Thomas F. Pettigrew, Linda R. Tropp, A Meta-Analytic Test of Intergroup…, 44

Categorization

• DEFINE: Explains the mechanism of publication bias that distorts meta-analytic reviews.
• XREF: connects to: Publication-status differences in priming effects disappear once correlated design variables are controlled. — Annetta Snell and Miron Zuckerman and Bonnie M. Le, Does Religious Priming Induce Greater…, 84; The intergroup contact-prejudice link survives file-drawer checks, indicating limited publication bias. — Thomas F. Pettigrew, Linda R. Tropp, A Meta-Analytic Test of Intergroup…, 104; The contact-prejudice effect may be partly an artifact of publication bias. — Thomas F. Pettigrew, Linda R. Tropp, A Meta-Analytic Test of Intergroup…, 108

Related

• Comparing published and unpublished studies tests whether reporting bias inflates effects. (similarity 0.89)
• The intergroup contact-prejudice link survives file-drawer checks, indicating limited publication bias. (similarity 0.87)
• Publication-status differences in priming effects disappear once correlated design variables are controlled. (similarity 0.87)
• A null correlation between sample size and effect size indicates minimal publication bias. (similarity 0.85)
• Subjective literature reviews suffer selection biases that meta-analysis avoids. (similarity 0.85)
• The contact-prejudice effect may be partly an artifact of publication bias. (similarity 0.84)
• Publication bias can be detected through sample-size and effect-size correlations. (similarity 0.84)
• Meta-analysis pools all studies to estimate effect sizes and moderators (similarity 0.83)
• Stronger contact effects in rigorous studies would confirm the contact-prejudice link. (similarity 0.82)
• Publication bias inflates the apparent effectiveness of prejudice-reduction programs (similarity 0.81)
• Publication bias is unlikely to fully explain the religious priming effect. (similarity 0.81)
• File-drawer tests assume uncovered unpublished studies form a random sample. (similarity 0.80)
• No meta-analysis of intergroup contact research existed before this study. (similarity 0.80)
• A meta-analysis synthesized 515 studies with 250,089 participants across 38 nations. (similarity 0.79)
• The publication effect on priming prejudice results vanishes once confounding moderators are controlled (similarity 0.79)