Reputation: 1947
In R, the plm function documentation of package plm, we can read about possibility of choose one of three effects individual
, time
, twoways
. Why such exists if I can just pick model type which already specifies which effect to use ? E.g. 'within' model will only use individual
and random
will always pick twoways
. To say more - for example pooling
model by definition takes no effect (no time
and no individual
) so choosing effect in this case is meaningless. What's the purpose of this additional input?
Upvotes: 0
Views: 277
Reputation: 46
How do you come to this conclusion? The within model can be used with "individual", "time" or "twoways". You should see different results for your model coefficients, when choosing a different effect. Also, for example, when you use "time" or "twoways", you should be able to get the specific time effects via
summary(fixef(yourmodel,type = "level", effect="time"))
.
(My plm package version is 2.2-4.)
Upvotes: 3