# Why pglm fails for within model?

Trying to run a panel logistic model. In the parameters a default NULL is specified for the "start" parameter.

My model is:

res<-pglm(DFLT_DEBT_01.3~NGDPRPC+NGDP_RPCH+BCA_NGDPD+LC_PER_USD+OFF_RSVA+M2 ,
index=c("Country","Date"),start=NULL,data=dat,family="binomial", model="within")


However, even if I explicitly set start=NULL I receive the message:

Error in prepare Fixed(start = start, activePar = activePar, fixed = fixed) :
argument "start" is missing, with no default


I'm not sure how I can specify starting values as I have not seen anywhere the precise order of specification of the parameters.

• Always add reproducible example. More often than not the problem is with the data or specification of the model. Without the data it is impossible to help with that problem. – mpiktas Apr 15 '15 at 6:48

If you look at the code for pglm, you can see that starting values are calculated with function starting.values. For family binomial the code calculates starting values only for model random and pooling, there is no variant for within. Hence the error. If you supply the starting values, the error is given in the function lnl.binomial. Looking at the code it is clear that model within is not supported.