Meta-Regression Methods for Detecting and Estimating Empirical Effects in the Presence of Publication Selection

This study investigates the small-sample performance of meta-regression methods for detecting and estimating genuine empirical effects in research literatures tainted by publication selection. Publication selection exists when editors, reviewers or researchers have a preference for statistically significant results. Meta-regression methods are found to be robust against publication selection. Even if a literature is dominated by large and unknown misspecification biases, precision-effect testing and joint precision-effect and meta-significance testing can provide viable strategies for detecting genuine empirical effects. Publication biases are greatly reduced by combining two biased estimates, the estimated meta-regression coefficient on precision (1/"Se") and the unadjusted-average effect. Copyright 2008 Blackwell Publishing Ltd and the Department of Economics, University of Oxford.