[R-meta] Dealing with effect size dependance with a small number of studies

[Danka Puric]

Hi everyone,

I have a (hopefully short) additional question. I just recently
remembered that we have another level of potential effect size
dependence in our data - the level of the journal article / paper.
Therefore, the theoretically most complete model would be:
es <- rma.mv(ES_g, V, random = ~ 1 | IDpaper / IDstudy / IDsubsample /
IDeffect, data=MA_dat)

For this model I'm getting zero variance (to four decimal places) for
IDstudy and IDsubsample random effects, which makes it (from what I
can tell) numerically identical to this simplified model:
es <- rma.mv(ES_g, V, random = ~ 1 | IDpaper / IDeffect, data=MA_dat)

I was planning on reporting the full model in the manuscript, noting
that the variances at certain levels are zero. When testing for the
effects of moderators I would also include all levels. Is this the
right way to go about this?

Thanks in advance,
Danka