Rosenthal was 2981 indicating that we would need to locate 2981 null studies for the combined p-value to exceed .05. There would need to be 30 missing studies for every observed study for the effect to be nullified. In comparison, Orwin's was 131, revealing that we would need to locate 131 studies with a mean standard difference in Ms of 0 to bring the combined standard difference in Ms under 0.1.
This large number of unpublished null trails led us to conclude that our finding were unlikely to be biased by the file-drawer problem