Dear all,
I am running a logistic regression and want to check for influential observations. To do that, I plot the standardized residuals for each paricipant. The plot seems a little strange, since one would expect the residuals to be in one cluster around y=0. Does anyone have any suggestions to why I get a plot like the one below (in the lower cluster, none of the observations have outcome = 0, whereas in the upper cluster, there are both outcomes = 0 and =1)?
Array
Output (Norwegian variable names):
Best,
Kjell Weyde
I am running a logistic regression and want to check for influential observations. To do that, I plot the standardized residuals for each paricipant. The plot seems a little strange, since one would expect the residuals to be in one cluster around y=0. Does anyone have any suggestions to why I get a plot like the one below (in the lower cluster, none of the observations have outcome = 0, whereas in the upper cluster, there are both outcomes = 0 and =1)?
Code:
predict stdres, rstandard scatter stdres PREG_ID_1569
Code:
logistic overweight c.noise##i.gender age_7y i.urbanity logincome i.education i.ethnicity i.emotional_7år dietscore_7y i.physact i.mat_smoke bmi_birth i.divorced if birthweight>2500 & zbfa_7år > -5 & zbfa_7år<5 & bmi_birth<25
Code:
Logistic regression Number of obs = 1,484
LR chi2(19) = 38.87
Prob > chi2 = 0.0046
Log likelihood = -581.96559 Pseudo R2 = 0.0323
overvekt | Odds Ratio Std. Err. z P>|z| [95% Conf. Interval]
--------------------------------------------------------------------------------------------------
overvekt | Odds Ratio Std. Err. z P>|z| [95% Conf. Interval]
---------------------------------+----------------------------------------------------------------
Len_vei_7åringer_livstid | 1.005131 .0137301 0.37 0.708 .9785777 1.032405
|
KJONN |
Pike | 2.371608 2.357581 0.87 0.385 .3379681 16.64217
|
KJONN#c.Len_vei_7åringer_livstid |
Pike | .9743111 .0196758 -1.29 0.198 .9365005 1.013648
|
age_7år | 1.000184 .0019205 0.10 0.923 .9964275 1.003956
|
sone_siste_adresse_7år |
Mellom Ring 2 og 3 | 1.137747 .2134702 0.69 0.492 .7876593 1.643435
Innenfor Ring 2 | 1.304274 .3594635 0.96 0.335 .7599305 2.238533
|
loginntekt | 1.173329 .4466114 0.42 0.675 .5564443 2.474104
|
mors_utdanning_num |
Univ./høyskole inntil 4 år | 1.414774 .2347284 2.09 0.037 1.022027 1.958448
Inntil videregående påbygning | 1.875568 .4195352 2.81 0.005 1.209852 2.907591
|
landbakgr_barn |
Ikke-vestlig | 1.509217 .3477814 1.79 0.074 .9607323 2.370834
|
emotional_7år |
Vansker siste året | 1.205125 .3618195 0.62 0.534 .6690715 2.17066
dietscore_7y | .9987875 .0417213 -0.03 0.977 .9202731 1.084
|
fysakt_7år |
3-7 t/uke | 1.258417 .2436777 1.19 0.235 .8609925 1.839288
Mindre enn 1-2 t/uke | 1.102782 .2616349 0.41 0.680 .692695 1.755646
|
røyk_mor_7år |
Ja | 1.511349 .364988 1.71 0.087 .9414586 2.42621
bmi_birth | 1.142935 .0669046 2.28 0.022 1.019047 1.281884
|
skilt_7år |
Foreldre bor sammen | 1.202277 .2949885 0.75 0.453 .7432853 1.944706
_cons | .0032108 .0179463 -1.03 0.304 5.61e-08 183.7438
--------------------------------------------------------------------------------------------------
Best,
Kjell Weyde