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  • Regression adjust

    Hello
    I am doing logistic regression adjust, but it only works for some outcomes, even though they are all binary.
    Below I have posted the code and table for a succesful regression for one symptom, and below the line I tried for another symptom and it shows these fail messages. What am I doing wrong?


    . teffects ra (any_skin_symptoms ib(first).age ib(first).smoking ib(first).tobacco ib(first).alcohol, logit) (types_of_sanit
    > ation_worker)

    Iteration 0: EE criterion = 4.529e-26
    Iteration 1: EE criterion = 9.946e-34

    Treatment-effects estimation Number of obs = 678
    Estimator : regression adjustment
    Outcome model : logit
    Treatment model: none
    Robust
    any_skin_symptoms Coefficient std. err. z P>z [95% conf. interval]
    ATE
    types_of_sanitation_worker
    (Collector vs Sweeper) .1002326 .0368271 2.72 0.006 .0280528 .1724124
    (Transporter/Waste vehicle driver vs Sweeper) .0204006 .0287798 0.71 0.478 -.0360068 .076808
    (Pickers of dumping site vs Sweeper) .0344529 .0387662 0.89 0.374 -.0415275 .1104333
    POmean
    types_of_sanitation_worker
    Sweeper .0643657 .0170494 3.78 0.000 .0309495 .0977818
    __________________________________________________ __________________________________________________ _
    . teffects ra (suffered_from_infection ib(first).age ib(first).smoking ib(first).tobacco ib(first).alcohol, logit) (types_of
    > _sanitation_worker)
    outcome model: perfect predictions detected; the model, as specified, is not identified
    1.types_of_sanitation_worker#1.smoking != 0 (n=1) predicts failure perfectly
    2.types_of_sanitation_worker#2.age != 0 (n=2) predicts failure perfectly
    2.types_of_sanitation_worker#1.smoking != 0 (n=1) predicts success perfectly
    4.types_of_sanitation_worker#2.age != 0 (n=2) predicts success perfectly
    4.types_of_sanitation_worker#1.smoking != 0 (n=1) predicts success perfectly
    4.types_of_sanitation_worker#1.alcohol != 0 (n=1) predicts failure perfectly
    r(322);

  • #2
    Originally posted by Sara Crowe View Post
    outcome model: perfect predictions detected; the model, as specified, is not identified
    This is the key line.The following link explains the problem of perfect prediction: https://stats.oarc.ucla.edu/other/mu...ith-the-issue/

    Comment


    • #3
      Thank you very much! I will try applying the suggested solutions!

      Comment

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