Hi everyone, I am using Stata 14.2.
I am doing a regression with a polynomial term and when doing the margins command, I get "not estimable" for all the results.
This happens when I try to use income^3, when using income^2 no problems arise.
I treat income as a continuous variable but it is coded 1-13.
Any ideas? Thanks for the help!
I am doing a regression with a polynomial term and when doing the margins command, I get "not estimable" for all the results.
This happens when I try to use income^3, when using income^2 no problems arise.
I treat income as a continuous variable but it is coded 1-13.
Code:
. reg bet_sjuk s1gr##c.tillgng_sjuk##c.income1##c.income1##c.income1 lrpown if working1==1 & income1>=6
Source SS df MS Number of obs = 2,147
F(40, 2106) = 29.77
Model 2692.35576 40 67.308894 Prob > F = 0.0000
Residual 4761.11979 2,106 2.26074064 R-squared = 0.3612
Adj R-squared = 0.3491
Total 7453.47555 2,146 3.47319457 Root MSE = 1.5036
bet_sjukvard Coef. Std. Err. t P>t [95% Conf. Interval]
s1gr
Resurs -138.6713 46.51002 -2.98 0.003 -229.8817 -47.4609
Resultat -91.91092 40.88065 -2.25 0.025 -172.0816 -11.74025
Privatisering 4.898225 41.07204 0.12 0.905 -75.64779 85.44424
Mix -78.76772 40.44625 -1.95 0.052 -158.0865 .5510494
tillgng_sjuk -5.225611 4.881832 -1.07 0.285 -14.79933 4.348107
s1gr#c.tillgng_sjuk
Resurs 17.80285 7.207972 2.47 0.014 3.667359 31.93834
Resultat 14.08524 6.567679 2.14 0.032 1.205422 26.96505
Privatisering .2917264 6.451758 0.05 0.964 -12.36076 12.94421
Mix 12.49007 6.413887 1.95 0.052 -.0881453 25.06829
income1 -13.90811 10.30591 -1.35 0.177 -34.11895 6.302722
s1gr#c.income1
Resurs 47.07528 15.06316 3.13 0.002 17.53504 76.61552
Resultat 32.90284 13.36904 2.46 0.014 6.684932 59.12076
Privatisering .3609681 13.39434 0.03 0.979 -25.90655 26.62849
Mix 27.47643 13.19461 2.08 0.037 1.600595 53.35227
c.tillgng_sjuk#c.income1 2.006988 1.583574 1.27 0.205 -1.098545 5.112522
s1gr#c.tillgng_sjuk#c.income1
Resurs -6.152494 2.330587 -2.64 0.008 -10.72299 -1.582
Resultat -5.089035 2.146292 -2.37 0.018 -9.29811 -.87996
Privatisering -.4396149 2.103008 -0.21 0.834 -4.563804 3.684575
Mix -4.387674 2.086859 -2.10 0.036 -8.480194 -.2951529
c.income1#c.income1 1.635636 1.096501 1.49 0.136 -.5147029 3.785975
s1gr#c.income1#c.income1
Resurs -5.157678 1.594157 -3.24 0.001 -8.283965 -2.031391
Resultat -3.721 1.426048 -2.61 0.009 -6.51761 -.9243901
Privatisering -.1705625 1.428451 -0.12 0.905 -2.971884 2.630759
Mix -3.09337 1.405816 -2.20 0.028 -5.850303 -.3364366
c.tillgng_sjuk#c.income1#c.income1 -.2382678 .1680466 -1.42 0.156 -.5678225 .0912869
s1gr#c.tillgng_sjuk#c.income1#c.income1
Resurs .6839332 .2462758 2.78 0.006 .2009638 1.166903
Resultat .5806964 .2287842 2.54 0.011 .1320298 1.029363
Privatisering .073177 .2240925 0.33 0.744 -.3662888 .5126429
Mix .4976741 .2218077 2.24 0.025 .0626891 .9326591
c.income1#c.income1#c.income1 -.0614903 .0381521 -1.61 0.107 -.1363101 .0133294
s1gr#c.income1#c.income1#c.income1
Resurs .1827555 .0550703 3.32 0.001 .0747576 .2907534
Resultat .1340927 .0496282 2.70 0.007 .0367673 .2314181
Privatisering .008471 .0497911 0.17 0.865 -.0891738 .1061159
Mix .1124804 .0489046 2.30 0.022 .0165741 .2083868
c.tillgng_sjuk#c.income1#c.income1#c.income1 .0090273 .0058305 1.55 0.122 -.0024069 .0204615
s1gr#c.tillgng_sjuk#c.income1#c.income1#c.income1
Resurs -.0245357 .0084965 -2.89 0.004 -.0411982 -.0078732
Resultat -.0211153 .0079573 -2.65 0.008 -.0367202 -.0055103
Privatisering -.0031784 .0078021 -0.41 0.684 -.018479 .0121221
Mix -.018219 .0076972 -2.37 0.018 -.033314 -.0031241
lrpown -.4086561 .0141641 -28.85 0.000 -.4364333 -.380879
_cons 44.82029 31.69731 1.41 0.158 -17.34102 106.9816
Code:
margins, at(s1gr=(1 2) tillgng_sjuk=(4 8) income1=(6(1)13))
Delta-method
Margin Std. Err. t P>t [95% Conf. Interval]
_at
1 . (not estimable)
2 . (not estimable)
3 . (not estimable)
4 . (not estimable)
5 . (not estimable)
6 . (not estimable)
7 . (not estimable)
8 . (not estimable)
9 . (not estimable)
10 . (not estimable)
11 . (not estimable)
12 . (not estimable)
13 . (not estimable)
14 . (not estimable)
15 . (not estimable)
16 . (not estimable)
17 4.150017 .5988989 6.93 0.000 2.975522 5.324512
18 . (not estimable)
19 . (not estimable)
20 . (not estimable)
21 . (not estimable)
22 . (not estimable)
23 . (not estimable)
24 . (not estimable)
25 . (not estimable)
26 . (not estimable)
27 . (not estimable)
28 . (not estimable)
29 . (not estimable)
30 . (not estimable)
31 . (not estimable)
32 . (not estimable)
