Hello, everyone! I have encountered unestimable margins when running a logistic regression with an interaction.
Here is my output.
After reading manuals and researching on this topic, it seems that it is likely caused by empty cells. However, I am using a large dataset and there is no empty cell when I run the crosstab.
When I add noestimcheck, the results show up and they look reasonable. Should I trust the results? I found out this old post http://statalist.1588530.n2.nabble.c...td3407157.html and it seems that noestimcheck needs to be used with great caution with interaction terms. I am using Stata 16.
Thanks!
Here is my output.
Code:
. logit homeown i.raceth##i.forborn $dems $ses yrsusa i.linguiso $other if both==1, nocons Iteration 0: log likelihood = -1276644.7 Iteration 1: log likelihood = -849822.09 Iteration 2: log likelihood = -846538.72 Iteration 3: log likelihood = -846524.62 Iteration 4: log likelihood = -846524.62 Logistic regression Number of obs = 1,841,809 Wald chi2(125) = 507020.07 Log likelihood = -846524.62 Prob > chi2 = 0.0000 ------------------------------------------------------------------------------------------------------------------------ homeown | Coef. Std. Err. z P>|z| [95% Conf. Interval] -------------------------------------------------------+---------------------------------------------------------------- raceth | 4. NHC | .6385632 .027372 23.33 0.000 .5849151 .6922114 5. NHJ | .5653426 .0400141 14.13 0.000 .4869164 .6437688 6. NHF | -.098571 .0338973 -2.91 0.004 -.1650085 -.0321335 7. NHI | -.1735716 .0397069 -4.37 0.000 -.2513957 -.0957475 8. NHK | -.2241101 .0483639 -4.63 0.000 -.3189015 -.1293186 9. NHV | .348966 .0560098 6.23 0.000 .2391888 .4587433 | 1.forborn | -1.316316 .0124516 -105.71 0.000 -1.340721 -1.291912 | raceth#forborn | 4. NHC#1 | .3350237 .0314141 10.66 0.000 .2734531 .3965943 5. NHJ#1 | -1.139156 .0558045 -20.41 0.000 -1.248531 -1.029781 6. NHF#1 | .0531232 .0382891 1.39 0.165 -.021922 .1281684 7. NHI#1 | .0593582 .0423115 1.40 0.161 -.0235708 .1422871 8. NHK#1 | -.0756405 .0529992 -1.43 0.154 -.179517 .028236 9. NHV#1 | .4663223 .0603573 7.73 0.000 .3480241 .5846204 | age | .0706146 .0014749 47.88 0.000 .0677239 .0735054 age2 | -.0002098 .0000164 -12.82 0.000 -.0002419 -.0001778 1.female | .006187 .0039075 1.58 0.113 -.0014716 .0138457 | marst3 | previously married | -1.198443 .0050531 -237.17 0.000 -1.208347 -1.188539 never married | -1.298763 .0049671 -261.47 0.000 -1.308498 -1.289027 | educ5 | HS graduate | .340975 .0098948 34.46 0.000 .3215815 .3603685 Some college | .5482986 .0096026 57.10 0.000 .5294779 .5671193 Bachelor's degree | .9143729 .0098288 93.03 0.000 .8951088 .9336369 Grad+ | .9483004 .0102377 92.63 0.000 .9282348 .968366 | logfinc | .1916358 .0013543 141.50 0.000 .1889814 .1942903 yrsusa | .0399718 .000417 95.86 0.000 .0391545 .0407891 1.linguiso | -.4252366 .0133153 -31.94 0.000 -.451334 -.3991391 1.mover | -1.289979 .005414 -238.27 0.000 -1.300591 -1.279368 | met2013 | 10580. albany-schenectady-troy, ny | -3.652022 .0430616 -84.81 0.000 -3.736421 -3.567623 10740. albuquerque, nm | -3.687591 .0502616 -73.37 0.000 -3.786102 -3.58908 ... 49660. youngstown-warren-boardman, oh-pa | -3.260858 .0470553 -69.30 0.000 -3.353084 -3.168631 ------------------------------------------------------------------------------------------------------------------------ . margins raceth, at(forborn=(0 1)) Predictive margins Number of obs = 1,841,809 Model VCE : OIM Expression : Pr(homeown), predict() 1._at : forborn = 0 2._at : forborn = 1 ------------------------------------------------------------------------------ | Delta-method | Margin Std. Err. z P>|z| [95% Conf. Interval] -------------+---------------------------------------------------------------- _at#raceth | 1#1. NHW | . (not estimable) 1#4. NHC | . (not estimable) 1#5. NHJ | . (not estimable) 1#6. NHF | . (not estimable) 1#7. NHI | . (not estimable) 1#8. NHK | . (not estimable) 1#9. NHV | . (not estimable) 2#1. NHW | . (not estimable) 2#4. NHC | . (not estimable) 2#5. NHJ | . (not estimable) 2#6. NHF | . (not estimable) 2#7. NHI | . (not estimable) 2#8. NHK | . (not estimable) 2#9. NHV | . (not estimable) ------------------------------------------------------------------------------
Code:
. tab raceth forborn if both==1,m | forborn raceth | 0 1 | Total ------------+----------------------+---------- 1. NHW | 1,564,121 116,852 | 1,680,973 4. NHC | 9,099 40,712 | 49,811 5. NHJ | 4,945 3,989 | 8,934 6. NHF | 4,850 21,479 | 26,329 7. NHI | 3,595 38,288 | 41,883 8. NHK | 2,442 13,908 | 16,350 9. NHV | 1,732 15,797 | 17,529 ------------+----------------------+---------- Total | 1,590,784 251,025 | 1,841,809
Thanks!