[R-meta] Welcome to the "R-sig-meta-analysis" mailing list

Dear all,


Thank you, professor Viechtbauer, for referring me to this list. 

Delving into metafor?s mechanics I noticed that when ?method = ?MN? ? is specified in escalc(), its calculation of sampling variance (vi) is ?vi <- sdi^2/ni?. I wondered why there is no option to use the(/a?) unbiased estimator ?vi <- sdi^2/ni-1?. I?m considered to bypass the escalc step and ?manually? compute vi as sdi^2/ni-1 ? but I?m hesitant because it isn?t an option in escalc() (when method = ?MN?, i.e. when obtaining the ?raw mean difference? for input as yi). Does anyone have any insights to share on why it is or is not a good idea to use the ?unbiased estimator? in the context of a REML MA on raw mean difference values? 

All best,

Anne-Wil