WWS509 - Stata Logs

6 Multinomial Response Models in Stata

This section deals with regression models for discrete data with more than two response categories. We will introduce the commands mlogit for multinomial logits, ologitfor ordered logits and oprobit for ordered probits. We will also use a couple of old friends: blogit for fitting hierarchical (nested) logit models and poisson for fitting log-linear models.

6.1 The Nature of Multinomial Data

Let us introduce the data on contraceptive use by age, found in Table 6.1 of the lecture notes. We will read the 7 by 3 table as 21 observations and treat the frequencies as weights:

. input ageg cuse cases

          ageg       cuse      cases
  1.    1   1     3
  2.    1   2    61
  3.    1   3   232
  4.    2   1    80
  5.    2   2   137
  6.    2   3   400
  7.    3   1   216
  8.    3   2   131
  9.    3   3   301
 10.    4   1   268
 11.    4   2    76
 12.    4   3   203
 13.    5   1   197
 14.    5   2    50
 15.    5   3   188
 16.    6   1   150
 17.    6   2    24
 18.    6   3   164
 19.    7   1    91
 20.    7   2    10
 21.    7   3   183
 22. end

. label define cuse 1 "sterilization" 2 "other method" 3 "no method"

. label values cuse cuse