How to fix invalid group specification error in xtdidregress?

[Chul-Kyoo Jung]

Apologies: this is my mistake: my post is supposed to be in General forum. Is there anyway to relocate this post or remove it?


Given the following data, I tried a couple of DiD command like xtdidgress (STATA18):

gen did = after * treated
encode country, gen(country1)
xtset country1 year

xtdidregress (gdppc) (did), group(country1) time(year)

keeps generating the following error:

invalid group specification
    None of the groups defined by country1 is a control.
r(198);

I am not sure why my code does not work and how to fix this invalid group specification error.

* Example generated by -dataex-. For more info, type help dataex
clear
input int year str22 country double(gdppc exports imports) long labor float(trade ln_gdppc ln_labor ln_trade after treated) byte merge1 float did long country1
2000 "Albania"   1960.881946020544 857470735.9349751 2300872129.784948  1318273   3158342912   7.58115 14.091833 21.873314 0 1 3 0 1
2001 "Albania"   2143.526277907566 990002860.8808274  2651107711.19258  1304987   3641110528  7.670208 14.081703 22.015554 0 1 3 0 1
2002 "Albania"   2247.497491299384 1025171413.592658  2911350528.93111  1308103   3936521984  7.717573 14.084088 22.093563 0 1 3 0 1
2003 "Albania"   2380.643997095389 1145867419.164587 3060633195.223174  1294847   4206500608  7.775126 14.073903 22.159897 0 1 3 0 1
2004 "Albania"   2522.448713619714  1357667966.99103 3312101590.431385  1281167   4669769728  7.832985 14.063282 22.264376 0 1 3 0 1
2005 "Albania"   2675.507936155238 1687131306.394109 3848503241.777667  1266464   5535634432  7.891894  14.05174  22.43447 0 1 3 0 1
2006 "Albania"   2851.367012185749 1972719243.547633  4183558822.96223  1249959   6156278272  7.955554  14.03862  22.54074 0 1 3 0 1
2007 "Albania"   3044.895819105146 2349749309.080778 4994570118.306822  1231498   7344319488  8.021222 14.023742 22.717194 0 1 3 0 1
2008 "Albania"   3298.478044285313  2241060080.40264 5175492730.913847  1212147   7416552960  8.101216 14.007904  22.72698 0 1 3 0 1
2009 "Albania"    3432.16997279698   2346648431.0909 5116479392.396209  1258916   7463128064  8.140948 14.045762  22.73324 1 1 3 1 1
2010 "Albania"   3577.113387840542 2797054267.483936 5087164545.338707  1270655   7884218880  8.182311 14.055043  22.78813 1 1 3 1 1
2011 "Albania"   3678.046737860349 2983732330.374774 5401870344.979011  1388801   8385602560  8.210137  14.14395 22.849783 1 1 3 1 1
2012 "Albania"   3736.339100713677 2992492280.656802 5040261183.147669  1328695   8032753664  8.225862 14.099708 22.806793 1 1 3 1 1
2013 "Albania"   3780.698202056765 3040042848.425611 5007820581.766235  1227940   8047863296  8.237664 14.020848  22.80867 1 1 3 1 1
2014 "Albania"   3855.759733947442  3075088501.78847 5221093227.894959  1256110   8296181760  8.257323  14.04353  22.83906 1 1 3 1 1
2015 "Albania"   3952.802538075274  3104896964.71229 5070976018.900984  1308343   8175873024   8.28218 14.084272 22.824453 1 1 3 1 1
2016 "Albania"   4090.371656677999 3457010821.060967  5421893718.36478  1354998   8878904320  8.316391  14.11931 22.906944 1 1 3 1 1
2017 "Albania"   4249.803733677256 3914838501.559224 5874936823.660885  1377319   9789774848  8.354628  14.13565 23.004604 1 1 3 1 1
2018 "Albania"    4431.53918098494 4072440421.167301 6015756951.463772  1409389  10088197120 8.3965025 14.158667  23.03463 1 1 3 1 1
2019 "Albania"   4543.386520186427 4179781429.471554 6153496458.037421  1433004  10333278208  8.421428 14.175283 23.058636 1 1 3 1 1
2020 "Albania"    4410.45516523171 3015234051.981862 4935756991.721656  1369908   7950990848  8.391733 14.130254  22.79656 1 1 3 1 1
2021 "Albania"   4830.596316916216 4417690606.932316 6500647673.954473  1377655  10918338560  8.482725 14.135893  23.11371 1 1 3 1 1
2000 "Algeria"   3138.231047505887 38581067530.45182 17551213963.21152  8926622  56132280320 8.0514145 16.004549 24.750977 0 . 1 . 2
2001 "Algeria"   3188.207270717673 41050255852.57413 18885106224.32076  9145785  59935363072  8.067214 16.028803  24.81653 0 . 1 . 2
2002 "Algeria"   3321.638849444479 43308019924.48602 23266450868.78375  9355943  66574471168  8.108213 16.051523 24.921587 0 . 1 . 2
2003 "Algeria"   3512.900199695449 46556121418.87327 24453039862.98143  9556009  71009165312  8.164197 16.072681 24.986074 0 . 1 . 2
2004 "Algeria"   3612.754164399913 48045917304.45602 27509669845.98296  9747177  75555586048  8.192225 16.092487 25.048134 0 . 1 . 2
2005 "Algeria"    3774.07249144514 50880626425.46498 29270288716.02691  9916026  80150913024  8.235909 16.109663  25.10718 0 . 1 . 2
2006 "Algeria"   3783.314203825792 49812133270.68735 28831234385.05457 10077550  78643363840  8.238356  16.12582  25.08819 0 . 1 . 2
2007 "Algeria"   3848.779512497945 49314011937.96015 32262151277.39559 10244513  81576165376  8.255511 16.142252 25.124804 0 . 1 . 2
2008 "Algeria"   3874.369338368776 48130475651.51955   37230522574.566 10402785   8.5361e+10  8.262138 16.157583 25.170155 0 . 1 . 2
2009 "Algeria"   3866.297025479813 43269297610.48782 41996029464.06922 10551825  85265326080  8.260053  16.17181 25.169033 1 . 1 . 2
2010 "Algeria"   3931.721347710451 43269297610.48782 43885850789.92656 10832191  87155146752  8.276833 16.198032 25.190956 1 . 1 . 2
2011 "Algeria"   3969.661577032352 42101026575.18684 41867101652.88074 10616990  83968131072  8.286436 16.177965 25.153704 1 . 1 . 2
2012 "Algeria"   4025.642803011689 40501187565.12249 47644761681.28753 11293832  88145952768   8.30044 16.239767  25.20226 1 . 1 . 2
2013 "Algeria"   4057.766136822925 38192619873.91051 52313948326.05371 11793700  90506567680  8.308388 16.283075  25.22869 1 . 1 . 2
2014 "Algeria"   4129.423902106026 38269005113.54319 56708319985.12886 11392848  94977327104  8.325893 16.248497 25.276903 1 . 1 . 2
2015 "Algeria"   4197.421360551422   38460350139.138 60621194064.23985 11709818  99081543680  8.342226 16.275938  25.31921 1 . 1 . 2
2016 "Algeria"   4246.243565422395 41152574649.27049 58923800630.71738 11918421 100076371968   8.35379 16.293596   25.3292 1 . 1 . 2
2017 "Algeria"   4218.083701294793 38642267595.32363 54740210786.10035 12073799  93382475776 8.3471365  16.30655  25.25997 1 . 1 . 2
2018 "Algeria"   4188.221757435173 37212503694.66647 52660082775.93166 12232256  8.98726e+10  8.340032 16.319588  25.22166 1 . 1 . 2
2019 "Algeria"   4153.004815940206 34942540969.31213 49026537064.22642 12413307  83969081344  8.331588  16.33428 25.153715 1 . 1 . 2
2020 "Algeria"   3873.510015074497 30854263675.68317 41231317670.88351 12016029  72085577728  8.261916 16.301752  25.00112 1 . 1 . 2
2021 "Algeria"   3943.171983377122 35081297799.18268 39499602329.38055 12312259  7.45809e+10   8.27974 16.326105  25.03515 1 . 1 . 2
2000 "Argentina" 10672.72203531211 44901264661.83915 39208026466.94148 16591106  84109287424  9.275447 16.624378  25.15538 0 . 1 . 3
2001 "Argentina" 10090.65344342863 46132004177.42078 33739846877.61813 16649055  79871852544  9.219365 16.627865  25.10369 0 . 1 . 3
2002 "Argentina"  8895.31964210751 47558846392.97437 16849830033.98695 16478531  64408678400  9.093281 16.617569 24.888514 0 . 1 . 3
2003 "Argentina" 9581.969792194684 50410174346.95029 23179531291.83373 16945135  7.35897e+10  9.167639  16.64549  25.02177 0 . 1 . 3
2004 "Argentina"  10341.6434058805 54500535536.25424 32479571849.74274 17425150  8.69801e+10  9.243934 16.673426 25.188946 0 . 1 . 3
2005 "Argentina" 11141.31067183753 61523927130.27948 37627009711.90277 17545905  99150938112  9.318415  16.68033  25.31991 0 . 1 . 3
2006 "Argentina"  11913.9585322637 64945397756.27386 41762919036.89604 17877291 106708320256  9.385466 16.699041 25.393366 0 . 1 . 3
2007 "Argentina" 12857.09257709611 70247833528.51355 49965275067.21821 17924078 1.202131e+11  9.461651 16.701656  25.51253 0 . 1 . 3
2008 "Argentina" 13246.63489171522 70767579313.63322 56741659099.45962 17966575 127509241856  9.491499 16.704023 25.571455 0 . 1 . 3
2009 "Argentina" 12336.86193852374 64152858356.33626  46291865845.2115 18324356 110444724224  9.420347 16.723742  25.42778 1 . 1 . 3
2010 "Argentina" 13551.33919402294 73068125669.10878 62588647492.18099 18255866 135656775680   9.51424 16.719997 25.633394 1 . 1 . 3
2011 "Argentina" 14200.26988906085    76099586869.35 76376060673.97023 18663922 152475648000  9.561016 16.742104  25.75027 1 . 1 . 3
2012 "Argentina" 13895.63370729862 72973178922.74258 72764799491.18575 18835226 145737973760   9.53933  16.75124 25.705076 1 . 1 . 3
2013 "Argentina" 14071.50868315572 70404347638.80727  75590170049.3954 18964106 145994514432  9.551908 16.758059 25.706835 1 . 1 . 3
2014 "Argentina" 13567.94841598087 65490710336.02921 66912422371.97636 19049721 132403134464  9.515466 16.762564  25.60912 1 . 1 . 3
2015 "Argentina" 13789.06042477202  63671789068.8987  70064879911.7042 19229475 133736669184 9.5316305 16.771955  25.61914 1 . 1 . 3
2016 "Argentina" 13360.21183459818 67057443560.29803 74145572745.46277 19404277 141203013632  9.500036 16.781004 25.673464 1 . 1 . 3
2017 "Argentina" 13595.03735510812 68811257871.94434 85700267253.02332 19580710 154511523840   9.51746 16.790056 25.763535 1 . 1 . 3
2018 "Argentina"   13105.397163317  69255776018.3655 81876889517.28857 20103008 151132667904   9.48078  16.81638 25.741425 1 . 1 . 3
2019 "Argentina"  12716.2242038544 76008924331.35214 66568179534.94145 20607477 1.425771e+11  9.450634 16.841164  25.68315 1 . 1 . 3
2020 "Argentina" 11341.26836558629 62546382587.70484 54279464556.85574 19406591 116825849856  9.336204 16.781124  25.48395 1 . 1 . 3
2021 "Argentina" 12402.49079123171 68311642980.87417 66231808716.36636 21206029 134543450112 9.4256525 16.869797  25.62515 1 . 1 . 3
2000 "Armenia"   1249.612147568568 925721968.3292271  2772344493.88811  1235341   3698066432  7.130589 14.026857 22.031076 0 1 3 0 4
2001 "Armenia"   1385.044814364463 1178101895.274112 2962750255.691311  1237463   4140852224  7.233488 14.028574 22.144167 0 1 3 0 4
2002 "Armenia"   1582.057644843091 1583599517.832443 3503420265.248455  1241360   5087020032  7.366482 14.031718  22.34996 0 1 3 0 4
2003 "Armenia"    1815.78825107558  2067475233.79072 4463653983.959955  1247177   6531129344  7.504275 14.036393 22.599846 0 1 3 0 4
2004 "Armenia"   2018.460170434296 2015694760.507496 4317744861.790298  1253765   6333439488   7.61009  14.04166  22.56911 0 1 3 0 4
2005 "Armenia"   2312.982895213299 2344004145.441441 4929000480.501121  1260793   7273004544  7.746293 14.047252 22.707436 0 1 3 0 4
2006 "Armenia"   2636.256686809872  2171975730.40491 5114378574.689456  1267543   7286354432  7.877115  14.05259  22.70927 0 1 3 0 4
2007 "Armenia"   3019.465604865895 2095777829.513626  5778981358.61692  1272744   7874759168 8.0128355 14.056685  22.78693 0 1 3 0 4
2008 "Armenia"   3250.498658621033  1821650394.06733 6199582120.044739  1267357   8021232640  8.086564 14.052444  22.80536 0 1 3 0 4
2009 "Armenia"   2810.192881672782 1631549237.165081  5012137467.34711  1281723   6643686912  7.941009 14.063716 22.616934 1 1 3 1 4
2010 "Armenia"   2889.566270494206 2063909295.263459 5653691266.170403  1338960   7.7176e+09  7.968862 14.107404  22.76677 1 1 3 1 4
2011 "Armenia"   3043.262830710318 2371396211.387967 5523658187.140568  1365792   7895054336  8.020685 14.127245 22.789503 1 1 3 1 4
2012 "Armenia"   3278.670496133968 2588036946.763781  5372726480.59743  1365906   7960763392  8.095193  14.12733  22.79779 1 1 3 1 4
2013 "Armenia"    3402.08390435316 2810608124.185466  5372726480.59743  1364749   8183334400  8.132143  14.12648 22.825365 1 1 3 1 4
2014 "Armenia"   3538.529444106904 2990487044.231936   5227662865.6213  1340268   8218149888  8.171467  14.10838  22.82961 1 1 3 1 4
2015 "Armenia"   3666.141875806497 3137020909.222351 4427830447.170573  1315555   7564851200  8.206895  14.08977  22.74678 1 1 3 1 4
2016 "Armenia"   3689.830136178396 3805206363.022725 4706783765.480478  1279945   8511990272  8.213336 14.062327  22.86474 1 1 3 1 4
2017 "Armenia"   3985.916756732912 4539611191.010181 5864652571.688245  1263559  10404263936  8.290523 14.049443  23.06548 1 1 3 1 4
2018 "Armenia"    4215.89945615491 4766591750.604708 6644651363.750361  1203266  11411243008  8.346619  14.00055 23.157866 1 1 3 1 4
2019 "Armenia"   4561.967865765993 5529246430.613426 7415430921.815311  1215999  12944676864  8.425509 14.011077  23.28395 1 1 3 1 4
2020 "Armenia"   4256.131290157068 3676948876.398755  5079570181.46165  1145653   8756518912  8.356116 13.951486 22.893064 1 1 3 1 4
2021 "Armenia"   4522.319107425487 4287322389.880959 5734834734.870184  1153003  10022157312   8.41678  13.95788 23.028065 1 1 3 1 4
2000 "Australia" 45893.81174773266 157926867545.2155 116583363457.4686  9523255 274510233600 10.734086 16.069248 26.338255 0 . 1 . 5
2001 "Australia"  46233.2485098235 171574836550.6688 115446569735.2524  9692915 2.870214e+11 10.741454 16.086906  26.38282 0 . 1 . 5
2002 "Australia" 47535.78956925602 170732656369.7531 117004692599.2691  9837966 287737348096 10.769238 16.101759 26.385313 0 . 1 . 5
2003 "Australia" 48454.28220399114 171593566017.8824 132446008165.9323 10013838 304039559168 10.788376 16.119478 26.440424 0 . 1 . 5
2004 "Australia" 49960.38024019271 173874040112.0645 150325468030.5238 10126070 3.241995e+11 10.818986 16.130625 26.504625 0 . 1 . 5
2005 "Australia" 50912.46689711488 179889428306.1205 169115157833.5331 10426942 3.490046e+11 10.837863 16.159904  26.57835 0 . 1 . 5
2006 "Australia" 51606.66552591471 185264785396.4285 183423654481.2047 10650659 3.686884e+11 10.851406 16.181133 26.633217 0 . 1 . 5
2007 "Australia" 52587.78599712376 192965825639.7101 202433548382.8531 10937240 3.953994e+11  10.87024 16.207684  26.70316 0 . 1 . 5
2008 "Australia" 53383.70750208182 200721762597.2384  231758056652.163 11228764 4.324798e+11  10.88526  16.23399   26.7928 0 . 1 . 5
2009 "Australia" 53272.98473354895 205575277980.3532 223154992552.9852 11471850 4.287303e+11 10.883184 16.255407 26.784094 1 . 1 . 5
2010 "Australia"  53607.9847584907 215249370718.0347 238651955364.7919 11661196 4.539013e+11 10.889453 16.271778 26.841146 1 . 1 . 5
2011 "Australia" 54132.52175364523 217073879162.1197 263541378196.1686 11842238 4.806153e+11  10.89919 16.287184  26.89833 1 . 1 . 5
end
label values merge1 _merge
label def _merge 1 "Master only (1)", modify
label def _merge 3 "Matched (3)", modify
label values country1 country1
label def country1 1 "Albania", modify
label def country1 2 "Algeria", modify
label def country1 3 "Argentina", modify
label def country1 4 "Armenia", modify
label def country1 5 "Australia", modify

[Joerg Luedicke (StataCorp)]

Your treatment indicator did has non-missing observations only for countries Albania and Armenia and it appears that both of these are among the countries receiving treatment. To identify ATET via DID, you will also need a group of never treated countries. That is, countries for which the treatment indicator is zero throughout the observation window. The error message points out that the data do not contain such control observations.

[Chul-Kyoo Jung]

Joerg Luedicke (StataCorp) Thank you, the problem solved. Please move this post to General forum if you can (I have already left message on Flag).