[Limdep Nlogit List] Error 215: Model too large

[alessandro.secchi at upf.edu]

Dear All,
I'm estimating a bivariate probit as the first stage of a more general  
heckman estimation.

The set of regressors is the same in both equations of the bivariate probit.
It includes a series of regional dummies (103) plus some other variables for
a total of 122 regressors.

When I try to estimate the bivariate probit with LIMDEP 9.0 for  
windows I get the following message:

Error 215: Model too large.K>150,>120 for SELE,>100 for 2SLS or MINI

My feeling is that the error is not related with memory space
(at the moment it is set on 80,000,000 cells, i.e. around 600M).

Is there any way to fix this problem ?

Note that I've also performed an experiment by assuming independence  
between the two equations of the probit (see below). However also in  
this case I got the Error 215 message after execturing the  
bivariateprobit command.

PROBIT;Lhs=Y1;Rhs=X1,X2,..,X122$
matrix; ba = b$
PROBIT;Lhs=Y2;Rhs=X1,X2,..,X122$
matrix; bb = b$
BIVARIATEPROBIT;Lhs=Y1,Y2;
Rh1=X1,...,X122;Rh2==X1,...,X122;Sel;Start=ba,bb,0; Load$

Any help would be appreciated.

Best,

Alessandro Secchi