Stata The Stata listserver
[Date Prev][Date Next][Thread Prev][Thread Next][Date index][Thread index]

st: nested logit model: how to interpret insignificant nesting parameter?


From   "Kelchtermans, Stijn" <Stijn.Kelchtermans@econ.kuleuven.ac.be>
To   <statalist@hsphsun2.harvard.edu>
Subject   st: nested logit model: how to interpret insignificant nesting parameter?
Date   Thu, 24 Mar 2005 10:21:56 +0100

All,

I have estimated a nested logit model explaining schooling choice, with all schooling options in one branch, and the outside option in the (degenerate) second branch. I have estimated the model sequentially because of the computational burden. 

Question: the nesting parameter that measure the dissimilarity among the schooling options comes out slighly negative (-.0459305) and insignificant. Does the insignificance imply that the nesting is inappropriate? 

The output (the estimates for the lower model were fixed to their first-step estimates):

Nested logit estimates

Levels             =          2                 Number of obs      =   546468

Dependent variable =     chosen                 LR chi2(14)        =  11816.01

Log likelihood     = -7198.8489                 Prob > chi2        =    0.0000

----------------------------------------------------------------------------
             |      Coef.   Std. Err.      z    P>|z|     [95% Conf. Int.]
-------------+--------------------------------------------------------------
option       |
       LSIZE |   .9400799          .        .       .            .         .
        VOCL |  -.6005096          .        .       .            .         .
    VOCLmale |   .2947062          .        .       .            .         .
     VOCLfor |   .4408798          .        .       .            .         .

[cut]

       ctrav |  -5.145888          .        .       .            .         .

-------------+--------------------------------------------------------------
STUDY        |
        NONE |   1.169447   .2569964     4.55   0.000     .6657433  1.673151
    NONEmale |   .1646824   .1107066     1.49   0.137    -.0522985  .3816633

 

[cut]

 

    NONEcath |  -.4957498   .1248174    -3.97   0.000    -.7403875   -.2511122

-------------+----------------------------------------------------------------

(incl. value |

 parameters) |

STUDY        |

        /YES |  -.0459305    .073946    -0.62   0.535    -.1908621     .099001

         /NO |          1          .        .       .            .           .

------------------------------------------------------------------------------

LR test of homoskedasticity (iv = 1): chi2(-164)=  -26.94 Prob > chi2 =      .

----------------------------------------------------------------------------

Many thanks,

Stijn Kelchtermans
Katholieke Universiteit Leuven
Belgium
Stijn.kelchtermans@econ.kuleuven.ac.be




*
*   For searches and help try:
*   http://www.stata.com/support/faqs/res/findit.html
*   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   |   What's new   |   Site index