Re: [Gretl-users] Limited Number of Independent Variables - Random Effects - Panel Data
On Wed, 13 May 2009, Nicolai C. Striewe wrote:
May I pose the following problem with the random-effects panel data
model
that I created:
The model consists of 54 independent variables (1 constant, 8 focus
variables, 5 control variables, and 40 time dummies). When I extend the
model by one focus variable it cuts off one time dummy. It seems to be a
restriction of gretl, that if more than 54 variables are specified in the
model, gretl leaves out all independent variables exceeding this limit
without a notification of omitting some variables.
Does gretl restrict the number of independent variables to 54? If yes, is
there a way around that restriction?
No, there's no such restriction. The variable is almost certainly
being dropped due to exact collinearity. We print that
information in the case of regular OLS estimation; we should
probably print it in the case of panel estimators too.
Allin Cottrell