Does the REML estimator (default) in the R metafor
package provides inverse-variance weighting?
1 Answer
The documentation for the metafor
package lays out how it does the weighting for both fixed- and random-effects models. Random-effects models will use weights that are—in part—calculated using the inverse of the variance. However, it also includes an estimate of $\tau^2$ in the denominator (added to the variance). This is specified on page six of the documentation I linked to above. There are various types of estimation methods you can use, and they don't involve changing how weights are determined. Different types of weighting (metafor
lets you define your own weights, if you want) can be used with different types of estimation.
metafor
package or (b) does the REML estimator do this by default? $\endgroup$rma(...)
? $\endgroup$