Specifies a hierarchical (level-3) structure including variables and effect type.
Arguments
- id
An id() object specifying the level-3 identifier: id(l3id)
- vars
A vars() object specifying level-3 variables, or NULL
- name
Unquoted variable name for level-3 labels (optional)
- type
Character; "RE" for random effects (default) or "FE" for fixed effects
- showFE
Logical; if TRUE and type = "FE", report the fixed effects (default: FALSE)