Here are my data and model:
m.brm <- brm(mean|se(sd) ~ 1 + (1+country||region) + (1+region||superregion) + superregion,data = datause, chains = 5, inits = "0", iter = 2000)
You can see the super region variable will restraint region variable.
However, I will get some impossible coefficient: like country Norway in Australasia:
, countryNorway
Estimate Est.Error Q2.5 Q97.5
Asia Pacific, high income 0.38582809 1.465504830 -1.23782812 5.02839963
Australasia 1.03690937 3.100617094 -1.60713437 9.84860255
Europe, western 0.02773833 0.004218536 0.01809817 0.03522186
How should we adjust it?