Hello,
If this has been answered somewhere else, please direct me to the correct thread. I tried looking up many threads on statalist and elsewhere, but I do not think I have found the answer yet.
Thanks in advance for answering.

I have code as follows:
Code:
reghdfe XVAR  ib19dif##i.treat controls, cluster(clustervar) absorb(year panel-id)
dif goes from 9 to 31 and clearly I wanted all the coefficients to be relative to the i19, hence the ib19 notation. But stata just decides to show everything relative to dif = 31 although it skips showing the interaction with dif = 19. This is the output from the above regression

Code:
                   |
   dif#treat |
       10 1  |   .1039422   1.283463     0.08   0.936    -2.479535     2.68742
       11 1  |  -.3399909   1.231326    -0.28   0.784    -2.818522     2.13854
       12 1  |   .7414249    1.05297     0.70   0.485    -1.378094    2.860944
       13 1  |   .6107571   1.295674     0.47   0.640      -1.9973    3.218814
       14 1  |     .39356   1.175573     0.33   0.739    -1.972745    2.759865
       15 1  |   2.063219   1.775728     1.16   0.251    -1.511136    5.637575
       16 1  |   .9777427   1.018561     0.96   0.342    -1.072515       3.028
       17 1  |   2.271153   1.020286     2.23   0.031     .2174245    4.324881
       18 1  |   1.978524   1.246361     1.59   0.119    -.5302711    4.487318
       20 1  |   -4.64421   1.556187    -2.98   0.005    -7.776653   -1.511768
       21 1  |  -5.596979   1.362165    -4.11   0.000    -8.338875   -2.855082
       22 1  |  -4.860838   1.235728    -3.93   0.000    -7.348229   -2.373447
       23 1  |  -3.936607   1.290388    -3.05   0.004    -6.534023   -1.339191
       24 1  |  -5.136231   1.183745    -4.34   0.000    -7.518986   -2.753475
       25 1  |  -4.734167   1.020978    -4.64   0.000    -6.789289   -2.679045
       26 1  |  -5.728412   1.284677    -4.46   0.000    -8.314334   -3.142491
       27 1  |  -5.731197   1.315701    -4.36   0.000    -8.379565   -3.082828
       28 1  |   1.189435   1.104055     1.08   0.287    -1.032912    3.411782
       29 1  |   1.532176   1.790198     0.86   0.397    -2.071306    5.135658
       30 1  |  -.1506353   .6733853    -0.22   0.824     -1.50609    1.204819
       31 1  |          0  (omitted)
It seems it doesn't matter if it were ib19, it could every well have been
Code:
reghdfe XVAR  ib16dif##i.treat controls, cluster(clustervar) absorb(year panel-id)
I get the same coefficients (i.e. relative to dif = 31) why does stata choose the last to omit.
Code:
       10 1  |  -.8738004   .9079232    -0.96   0.341    -2.701355    .9537542
       11 1  |  -1.317734   .8320499    -1.58   0.120    -2.992563     .357096
       12 1  |  -.2363178   .8177951    -0.29   0.774    -1.882454    1.409818
       13 1  |  -.3669855   1.102138    -0.33   0.741    -2.585474    1.851503
       14 1  |  -.5841827    .752915    -0.78   0.442    -2.099722    .9313567
       15 1  |   1.085477   1.601499     0.68   0.501    -2.138174    4.309127
       17 1  |    1.29341   .8236691     1.57   0.123    -.3645499     2.95137
       18 1  |   1.000781   1.044988     0.96   0.343    -1.102671    3.104233
       19 1  |  -.9777427   1.018561    -0.96   0.342       -3.028    1.072515
       20 1  |   -4.64421   1.556187    -2.98   0.005    -7.776653   -1.511768
       21 1  |  -5.596979   1.362165    -4.11   0.000    -8.338875   -2.855082
       22 1  |  -4.860838   1.235728    -3.93   0.000    -7.348229   -2.373447
       23 1  |  -3.936607   1.290388    -3.05   0.004    -6.534023   -1.339191
       24 1  |  -5.136231   1.183745    -4.34   0.000    -7.518986   -2.753475
       25 1  |  -4.734167   1.020978    -4.64   0.000    -6.789289   -2.679045
       26 1  |  -5.728412   1.284677    -4.46   0.000    -8.314334   -3.142491
       27 1  |  -5.731197   1.315701    -4.36   0.000    -8.379565   -3.082828
       28 1  |   1.189435   1.104055     1.08   0.287    -1.032912    3.411782
       29 1  |   1.532176   1.790198     0.86   0.397    -2.071306    5.135658
       30 1  |  -.1506353   .6733853    -0.22   0.824     -1.50609    1.204819
       31 1  |
0 (omitted)

Or Is the problem reghdfe - see for example this --. https://github.com/sergiocorreia/reg...ment-412606099

Any help would be appreciated greatly