[Limdep Nlogit List] help request

[Edoardo Marcucci]

Dear Limdep users,

We would like to ask a question concerning a problem we have  
encountered and are not able to solve. The manual is not very helpful  
on this specific point.

We are trying to estimate  a random parameter model with heterogeneity  
in variance attributable to choice-invariant characteristics.

the manual (N17-26) shows the code for the heterogeneity both in mean  
and variance together

RPL =  AGE, SEX;
HFR = INCOME, FAMILY, URBAN;
FCN = GC(N), TTIME (N|#01!101)

WE WOULD LIKE TO STUDY ONLY HETEROGENEITY IN VARIANCE.


FOLLOWING THIS EXAMPLE,

RPL;
HFR = INCOME, FAMILY, URBAN;

... WE DO NOT KNOW HOW TO CODE FCN.

WE HAVE TRIED BOTH:
(WE ACTUALLY USED U INSTEAD OF N)

1) FCN = GC(N), TTIME (N|!101)
2)FCN = GC(N), TTIME (N|#!101)

but in both cases we could not run the model.

More in detail:
-  in the first case, the error message was "ERROR 1071: In FCN =  
name(type|value), invalid value was found."
-  in the second case, the error message was "ERROR 1071: the #dddd  
format is used when ; RPL= list is present"


Any help on this point is much appreciated.

best regards
========================
Edoardo Marcucci
DIPES -
Università degli Studi di Roma Tre
Via G. Chiabrera, 199 - 00145 ROMA
tel. ++39  0657335294
fax. ++39 0657335282
cell. ++39 3316876905
mail edoardo.marcucci at uniroma3.it
========================