Hi statalist community,

I am using xthybrid command for the analysis of data. How to handle interaction terms, it has not been specified by Schunck and Perales ( 2017). Since I have two categorical independent variables, whose interaction is important to know.

In xthybrid output that is below, I want to study the interaction of stud_SCST and Teach_SCST (within effect) on the outcome variable. Can anyone suggest, how that can be done? Or steps to take, going further.

Code:
. xthybrid Positive_disc01    stud_SCST stud_OBC Teach_SCST Teach_OBC        Teach_nature_1 Teach_nature_2 Teach_gender_
> 1   course1_com course1_eco course1_eng course1_hin course1_his course1_mat course1_pol   sem_1 sem_2 sem_3 sem_4 sem_
> 5 attendence_percent   , clusterid ( group_teacherID_paper ) se  test   p   link(logit) family(bernoulli)

The variable 'Teach_SCST' does not vary sufficiently within clusters
and will not be used to create additional regressors.
[~0% of the total variance in 'Teach_SCST' is within clusters]
The variable 'Teach_OBC' does not vary sufficiently within clusters
and will not be used to create additional regressors.
[~0% of the total variance in 'Teach_OBC' is within clusters]
The variable 'Teach_nature_1' does not vary sufficiently within clusters
and will not be used to create additional regressors.
[~0% of the total variance in 'Teach_nature_1' is within clusters]
The variable 'Teach_nature_2' does not vary sufficiently within clusters
and will not be used to create additional regressors.
[~0% of the total variance in 'Teach_nature_2' is within clusters]
The variable 'Teach_gender_1' does not vary sufficiently within clusters
and will not be used to create additional regressors.
[~0% of the total variance in 'Teach_gender_1' is within clusters]
The variable 'course1_com' does not vary sufficiently within clusters
and will not be used to create additional regressors.
[~0% of the total variance in 'course1_com' is within clusters]
The variable 'sem_1' does not vary sufficiently within clusters
and will not be used to create additional regressors.
[~0% of the total variance in 'sem_1' is within clusters]
The variable 'sem_2' does not vary sufficiently within clusters
and will not be used to create additional regressors.
[~0% of the total variance in 'sem_2' is within clusters]
The variable 'sem_3' does not vary sufficiently within clusters
and will not be used to create additional regressors.
[~0% of the total variance in 'sem_3' is within clusters]
The variable 'sem_4' does not vary sufficiently within clusters
and will not be used to create additional regressors.
[~0% of the total variance in 'sem_4' is within clusters]
The variable 'sem_5' does not vary sufficiently within clusters
and will not be used to create additional regressors.
[~0% of the total variance in 'sem_5' is within clusters]

Hybrid model. Family: bernoulli. Link: logit.

+-----------------------------------+
|             Variable |   model    |
|----------------------+------------|
| Positive_disc01      |            |
|        R__Teach_SCST |    -0.2539 |
|                      |     0.3005 |
|                      |     0.3981 |
|         R__Teach_OBC |     0.1782 |
|                      |     0.3008 |
|                      |     0.5537 |
|    R__Teach_nature_1 |     0.0376 |
|                      |     0.2425 |
|                      |     0.8767 |
|    R__Teach_nature_2 |  (omitted) |
|                      |            |
|                      |            |
|    R__Teach_gender_1 |    -0.3657 |
|                      |     0.3221 |
|                      |     0.2562 |
|       R__course1_com |    -2.6670 |
|                      |     0.6928 |
|                      |     0.0001 |
|             R__sem_1 |    -0.7267 |
|                      |     0.4611 |
|                      |     0.1150 |
|             R__sem_2 |    -0.6509 |
|                      |     0.4247 |
|                      |     0.1254 |
|             R__sem_3 |    -0.3182 |
|                      |     0.3366 |
|                      |     0.3444 |
|             R__sem_4 |     0.4698 |
|                      |     0.2948 |
|                      |     0.1110 |
|             R__sem_5 |  (omitted) |
|                      |            |
|                      |            |
|         W__stud_SCST |    -0.1963 |
|                      |     0.0659 |
|                      |     0.0029 |
|          W__stud_OBC |    -0.1427 |
|                      |     0.0653 |
|                      |     0.0290 |
|       W__course1_eco |     0.1309 |
|                      |     0.3041 |
|                      |     0.6668 |
|       W__course1_eng |     0.4095 |
|                      |     0.3379 |
|                      |     0.2256 |
|       W__course1_hin |     0.4922 |
|                      |     0.3608 |
|                      |     0.1725 |
|       W__course1_his |    -0.1280 |
|                      |     0.3773 |
|                      |     0.7345 |
|       W__course1_mat |     0.1302 |
|                      |     0.4678 |
|                      |     0.7808 |
|       W__course1_pol |  (omitted) |
|                      |            |
|                      |            |
| W__attendence_perc~t |     0.0100 |
|                      |     0.0016 |
|                      |     0.0000 |
|         B__stud_SCST |    -0.9315 |
|                      |     1.8668 |
|                      |     0.6178 |
|          B__stud_OBC |    -1.7112 |
|                      |     2.9201 |
|                      |     0.5579 |
|       B__course1_eco |    -2.3956 |
|                      |     0.6492 |
|                      |     0.0002 |
|       B__course1_eng |    -3.5290 |
|                      |     0.6188 |
|                      |     0.0000 |
|       B__course1_hin |    -1.5348 |
|                      |     0.3884 |
|                      |     0.0001 |
|       B__course1_his |    -2.9572 |
|                      |     0.7245 |
|                      |     0.0000 |
|       B__course1_mat |    -2.4438 |
|                      |     0.7351 |
|                      |     0.0009 |
|       B__course1_pol |  (omitted) |
|                      |            |
|                      |            |
| B__attendence_perc~t |     0.0371 |
|                      |     0.0131 |
|                      |     0.0046 |
|                _cons |     1.0844 |
|                      |     1.2169 |
|                      |     0.3729 |
|----------------------+------------|
|   var(_cons[group~r])|            |
|                _cons |     1.7310 |
|                      |     0.2225 |
|                      |     0.0000 |
|----------------------+------------|
| Statistics           |            |
|                   ll | -5185.5979 |
|                 chi2 |   193.1889 |
|                    p |     0.0000 |
|                  aic | 10425.1959 |
|                  bic | 10619.3819 |
+-----------------------------------+
                       Legend: b/se/p
Level 1: 9819 units. Level 2: 201 units.

Tests of the random effects assumption:
  _b[B__stud_SCST] = _b[W__stud_SCST]; p-value: 0.6939
  _b[B__stud_OBC] = _b[W__stud_OBC]; p-value: 0.5913
  _b[B__course1_eco] = _b[W__course1_eco]; p-value: 0.0004
  _b[B__course1_eng] = _b[W__course1_eng]; p-value: 0.0000
  _b[B__course1_hin] = _b[W__course1_hin]; p-value: 0.0001
  _b[B__course1_his] = _b[W__course1_his]; p-value: 0.0005
  _b[B__course1_mat] = _b[W__course1_mat]; p-value: 0.0031
  _b[B__course1_pol] = _b[W__course1_pol]; p-value:      .
  _b[B__attendence_percent] = _b[W__attendence_percent]; p-value: 0.0400

.

regards,
ajay