QII  - exercise on mnl (uncond and cond)

Due:  Feb. 25, 2009


The next exercises use dutch election  data - the codebook is
 dutch271codebook.txt (4 main parties only). The Stata data are
 dutch271uncond.dta and dutch271cond.dta (for unconditional and
 conditional analyses, the data setups are different). The stata files
 themselves are also somewhat self documenting. The data are for the
 1971(!) Dutch parliamentary election.

1.  Take an unconditional (mlogit) model  that you
    like.  The depedendent variable, party,  is vote for one of the four
    biggest parties/ It  should have political variables (attitudes) as well as
    sociological variables. Make sure to set the baseline party
    yourself so Stata does not choose for you.
conditional mnl. Choose a baseline party and code it zero. Then
    do an unconditional logit analysis on the 4 major parties (these
    are the only ones in the data set)

a. Interpret A FEW interestng results.

b. Do a test of a hypothesis that one variable of interest has no
   effect on vote.

c. Redo with new baseline party. Check out that the results on one
   interesting condition change in the way discussed in class.

d. Calculate one interesting change in odds (for party 1 vs 0 and
   party 3 vs 4). Calculate both the estimates and their standard errors, using methods discussed in MUS or Clarify.


Now look at a conditional model assuming IIA (so use clogit.)  This
uses the  dutch271cond.dta (surprise!) data set. Use the command clogit.


Try to make the below as close to your moglit model so that
comparisons make sense. To add variables that do not differ across
alternatives please look at the ado file on the web or remember what i
did in class. 

a. Start with totally conditional variables only, that is, those that
   are attributes of the individual and choice, and vary over the four
   choices for each individual. These are the disleft and related
   variables. Run clogit on some of these. Interpret the findings. How
   does this analysis differ from using the unconditional variables
   like left? 

b.  Drop one choice  and   do an eyeball test of iia. What do you find?  

c Now look at the unconditional (attributes of individuals) variables
   in the equation. Interpret the
   results.