Extract the Random Effects
Function to calculate the random effects from a plm object
(random effects model).
## S3 method for class 'plm' ranef(object, effect = NULL, ...)
object |
an object of class |
effect |
|
... |
further arguments (currently not used). |
Function ranef calculates the random effects of a fitted random
effects model. For one-way models, the effects of the estimated
model are extracted (either individual or time effects). For
two-way models, extracting the individual effects is the default
(both, argument effect = NULL and effect = "individual" will
give individual effects). Time effects can be extracted by setting
effect = "time".
Not all random effect model types are supported (yet?).
A named numeric with the random effects per dimension (individual or time).
Kevin Tappe
fixef() to extract the fixed effects from a fixed
effects model (within model).
data("Grunfeld", package = "plm")
m1 <- plm(inv ~ value + capital, data = Grunfeld, model = "random")
ranef(m1) # individual random effects
# compare to random effects by ML estimation via lme from package nlme
library(nlme)
m2 <- lme(inv ~ value + capital, random = ~1|firm, data = Grunfeld)
cbind("plm" = ranef(m1), "lme" = unname(ranef(m2)))
# two-ways RE model, calculate individual and time random effects
data("Cigar", package = "plm")
tw <- plm(sales ~ pop + price, data = Cigar, model = "random", effect = "twoways")
ranef(tw) # individual random effects
ranef(tw, effect = "time") # time random effectsPlease choose more modern alternatives, such as Google Chrome or Mozilla Firefox.