Hello everyone,
I have a question on nlogit and constraints. I have 2 nests with only
1 alternative. Thus, when I ran the -nlogit-, I got the following
result.
. nlogit choice price2 ndays Mtotal_ads||type: sex age, base
(generic)||prescribe:, nolog notree noconstant case(id)
note: branch 1 of level 1 is degenerate and the associated dissimilarity
parameter ([generic_tau]_cons) is not defined; see help nlogit for
details
note: branch 2 of level 1 is degenerate and the associated dissimilarity
parameter ([breakthrough_tau]_cons) is not defined; see help nlogit
for details.
I tried to follow the instruction in the help by running the
following. But it did not work.
. constraint 1 [breakthrough_tau]_cons = 1
. constraint 2 [generic_tau]_cons = 1
. nlogit choice price2 ndays Mtotal_ads||type: sex age, base
(generic)||prescribe:, nolog notree noconstant case(id) constraint (1
2)
option constraint() not allowed equation 3 defining level 2 is
improperly specified
r(198);
. nlogit choice price2 ndays Mtotal_ads||type: sex age, base
(generic)||prescribe:, nolog notree noconstant case(id) constraint (1)
constraint (2)
option constraint() not allowed equation 3 defining level 2 is
improperly specified
r(198);
Would anyone have any suggestion on how specify -nlogit- when you have
2 constraints? Any help will be appreciated.
Cielo Magno
*
* For searches and help try:
* http://www.stata.com/help.cgi?search
* http://www.stata.com/support/statalist/faq
* http://www.ats.ucla.edu/stat/stata/
