[Limdep Nlogit List] double hurdle again

[Brett Smith]

Dear List, 

I asked a question about the double hurdle model a week or so ago. The
reason being that it is unlikely (fails likelihood test) that the
restrictions of the Tobit regression apply to the data. 
After fishing though the manuals I cannot see how to run a double hurdle
model in limdep. I am sure it is obvious...but just not seeing it. I have
added some code below which is using the minimize function (based on Jones
1992). 

I would like to ask the group if this is the correct (only, easiest) way to
estimate the double hurdle.

Thank you again,

Brett 



CREATE;ZERO = 0$

NAMELIST	;ProbReg = Z, ZERO, ZERO....? Repeat zero for the number of
vars in X
		;TrunReg = ZERO....,X,ZERO$  ? repeat zero for the number of
vars in Z, and one for SE in truncated regression

?run probit and  censored regresseion for start values

Probit; LHS= Travel; Rhs=Z$
Matrix; Bprob=b$? save probit parameters
Trunc; Lhs=y; Rhs=X$
Matrix; btrunc=b$? 
Matrix; bstart= bprob,_btrunc $ ? can't remember syntax but combine the two
vectors 

?Double hurdle model
MINIMIZE	;START= bstart
		;LABELS = B1 ,B2, B3, .... ,SE
		;FCN = - (1 - Travel)*LOG( 1 - PHI(b1'ProbReg)*PHI(
(b1'TruncReg)/SE) ))          ?log likelihood for travel
			 - Travel*(LOG(PHI(b1'ProbReg)) + LOG(NOl((Y -
(b1'TruncReg)/SE)))/SE)$    ? Log likelihood for observations greater than
zero