[R-meta] Replicating Three-Level Model with Fixed Effects

[Michael Dewey]

Dear Andrew

The difference you report is about 2.5%. With possibly different 
hardware, different fitting algorithm, ..., I would not be too concerned 
myself. Other readers on this site might have a different view though.

Michael

On 10/12/2018 18:01, Andrew Loignon wrote:
> Hi everyone,
> 
> As part of a separate project, I've been familiarizing myself with multi-level meta-analyses. While working through the example provided on the metafor package's website (http://www.metafor-project.org/doku.php/analyses:konstantopoulos2011), I ran into some difficulties replicating the three-level model described by Konstantopolous (2011, "Fixed effects and variance components estimation in
> three-level meta-analysis").
> 
> Specifically, I can replicate Konstantopolous' two-level model using year as a fixed effect (Table 4 in the research article) using the following code:
> 
> m0.ml <- rma.mv(yi, vi,
>                  random = ~ 1| study,
>                  mods = ~ I(year-mean(year)),
>                  method="ML",
>                  digits=3,
>                  data=dat.konstantopoulos2011
>                  )
> summary(m0.ml)
> 
> However, when I extend the model to include the higher-level nesting variable (i.e., district), the intercept diverges from what Konstantopolous reports (Table 5 in the research article). Right now, I'm using the following code:
> 
> m1.ml <- rma.mv(yi, vi,
>                  random = ~ 1| district/study,
>                  mods = ~ I(year-mean(year)),
>                  method="ML",
>                  digits = 3,
>                  data=dat.konstantopoulos2011)
> summary(m1.ml)
> 
> With this model, I find an intercept of .178, while Konstantopolous reports a value of .183.
> 
> Any suggestions for how to reconcile these differences would be very much appreciated.
> 
> Best,
> 
> Andrew
> Andrew C. Loignon
> Assistant Professor
> 2716 Business Education Complex
> Rucks Department of Management
> E. J. Ourso College of Business
> Louisiana State University
> Baton Rouge, LA 70808
> Email: aloignon using lsu.edu<mailto:aloignon using lsu.edu>
> Phone: 225-578-6148
> 
> 
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-- 
Michael
http://www.dewey.myzen.co.uk/home.html