SO5032: Lab Materials
Table of Contents
1. Week 11 Lab: Multinomial Regression
1.1. Multinomial logistic regression
Load this BHPS excerpt:
use http://teaching.sociology.ul.ie/so5032/bhpsqual.dta
vote
has four categories. Examine bivariate
relationships between vote and some of the other variables, by cross-tabulating vote and any categorical variables, or looking at how the mean value of quantitative variables differ by vote.
Then search for a multinomial logistic regession that makes sense:
mlogit vote
indvars….
It is better to have a base category that is easily interpretable, and
the default here will use the biggest category ("Other/nationalist"). To
avoid this, use the baseoutcome(1)
option, which will force category
one as the base. Use the likelihood-ratio test for each variable, since
there are three times as many parameters as usual.
Use predict
to generate predicted values (note you have
to supply one variable name to hold the prediction for each category). How often is
the most probable predicted category the same as the observed one?