Bookmark and Share

Notice: On March 31, it was announced that Statalist is moving from an email list to a forum. The old list will shut down at the end of May, and its replacement, statalist.org is already up and running.


[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

st: Nested Logit Model


From   Luis Felipe Correa Smits <felipe.correa.smits@gmail.com>
To   statalist@hsphsun2.harvard.edu
Subject   st: Nested Logit Model
Date   Wed, 2 Nov 2011 13:20:02 -0300

Dear All,

I’m quite new to stata so I don’t know If I have a command or database
issue. So here I go:

I’m trying to solve a model for my thesis dissertation on the
probability for a pharmacy to enter and then locate in a Chilean
district. My ideal tree should be:


                 N
          /              \
        /                  \
      /                       \
Enter                Not Enter
   |                    /        |    \
   |                  /          |      \
   |                /            |        \
   0     Location=1       …      N

I generated the nlgoit tree with the district=0 for the decision not
to enter the industry, and all the observed districts for the decision
to enter (nlogitgen type=district (No: 0, Yes: 1|…|N). Then I
generated the “chosen” variable based on whether there’s a pharmacy on
the district or not.

Then I tried to run the regression (nlogit   chosen
number_of_stores_pharmacy_chain1    number_of_stores_pharmacy_chain2
 number_of_stores_pharmacy_chain3
number_of_stores_independent_pharmacies
type_of_competitor_base_on_distance[inmediate; nearby; far away]
population_between_0_to_5_years_old  population_more_than_65_years_old
 median_rent  district_area[sq miles] business_density||type:
income_per_capita urban_population rural_population||district:,
case(district_id)).

But I get:
note: 334 cases (1336 obs) dropped due to no positive outcome or
multiple positive outcomes per case
no cases remain after removing invalid observations
r(2000);


I don’t know what I’m doing wrong. Can anyone help me please?

Thanks!


Best Regards

Felipe Correa

*
*   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/


© Copyright 1996–2014 StataCorp LP   |   Terms of use   |   Privacy   |   Contact us   |   Site index