[Limdep Nlogit List] working nlogit with >11 variables

[Marit Kragt]

Dear Limdep users,

I have recently started using NLOGIT4.0 to analyse discrete choice data. There are a couple of issues with the program that I nor my colleagues here can solve. I am hoping to get some help from you.

1) Every time I try to run a simple conditional logit model with more than 11 explanatory variables the program gets stuck. There is no problem whatsoever with the dataset (no missing data, no collinearity). I don't understand why the model doesn't accept more variables. I am using the command NLOGIT
;lhs=choice, cset, altij
;choices=SQ,change1,change2
;Model:
U(SQ) = ASCSQ + cost*cost + env1*attribute1 + env2*attribute2 + env3*attribute3 + env4*attribute4 + visit*ascvis + gender*ascgen + income*ascincom + education*asceduc + hhsize*aschhsize + farm*ascfarm/
U(change1) = cost*cost + env1*attribute1 + env2*attribute2 + env3*attribute3 + env4*attribute4 + visit*ascvis + gender*ascgen + income*ascincom + education*asceduc + hhsize*aschhsize + farm*ascfarm/
U(change2) = cost*cost + env1*attribute1 + env2*attribute2 + env3*attribute3 + env4*attribute4 + visit*ascvis + gender*ascgen + income*ascincom + education*asceduc + hhsize*aschhsize + farm*ascfarm$

2) Every time I open the HELP function it give me an error "There was a problem running the macro (1037)". Clicking "Help Topics" in the appearing screen does not do anything. Why does the help function not work correctly in NLOGIT4.0?
 
3) And lastly, I was wondering if anyone has an example of how to calculate WTP using bootstrapping? I have done parametric bootstrapping for logit models in other software programs, but am not positive on how to use this approach in NLOGIT. Since the help function doesn't work, it is hard to be sure. 
I suspect I need to use the PROCEDURE command to estimate a model and calculate the WTP based on this model, and then EXECUTE ;N = #repl ;Bootstrap = ...$
 
 
Thank you very much for your time, your feedback is much appreciated!
 
Regards,
Marit

----- 
Marit Kragt 
PhD scholar 

Crawford School of Economics and Government & Integrated Catchment Assessment and Management Centre (iCAM)
Building 13, Ellery Crescent 
The Australian National University 
Canberra ACT 0200 Australia 

T: +61 2 6125 6557 
W: http://icam.anu.edu.au, http://www.crawford.anu.edu.au/students/showphd.php?surname=Kragt