I am currently running Stata14 to analyse a dataset of 228 observations. The dependent variable is binary and so I am trying logit, probit and heckman commands to analyse. When I run the logit command without including the option to 'retain perfect predictor variables, Stata returns the following:
Code:
 logit WTPPer Age Income EducationBase Household FishAssocMem CommMem BidAmt

outcome does not vary; remember:
                                  0 = negative outcome,
        all other nonmissing values = positive outcome
Having included 'perfect predictor variables', output I have received so far is baffling because of the amount of missing information. Below are some examples. For the logit and probit, no z, P-values and confidence intervals are given. What does that mean? Listwise deletion has eliminated 10 observations for missing data but I don't know why logit and probit reports 'omitted' variables. The Heckan models' Chi square show a good overall fit but again there are missing z and P-values etc.
Code:
.
logit WTPPer Age Income EducationBase Household FishAssocMem CommMem BidAmt, asis

Iteration 0:   log likelihood = -151.10609  
Iteration 1:   log likelihood =          0  
Iteration 2:   log likelihood =          0  

Logistic regression                             Number of obs     =        218
                                                Wald chi2(0)      =          .
Log likelihood =          0                     Prob > chi2       =          .

-------------------------------------------------------------------------------
       WTPPer |      Coef.   Std. Err.      z    P>|z|     [95% Conf. Interval]
--------------+----------------------------------------------------------------
          Age |          0  (omitted)
       Income |   5.62e-15          .        .       .            .           .
EducationBase |   6.00e-14          .        .       .            .           .
    Household |          0  (omitted)
 FishAssocMem |  -6.00e-14          .        .       .            .           .
      CommMem |          0  (omitted)
       BidAmt |          0  (omitted)
        _cons |      33.75          .        .       .            .           .
-------------------------------------------------------------------------------
Note: 0 failures and 218 successes completely determined.

. probit WTPPer Age Income EducationBase Household FishAssocMem CommMem BidAmt, asis

Iteration 0:   log likelihood = -151.10609  
Iteration 1:   log likelihood =          0  
Iteration 2:   log likelihood =          0  

Probit regression                               Number of obs     =        218
                                                Wald chi2(0)      =          .
Log likelihood =          0                     Prob > chi2       =          .

-------------------------------------------------------------------------------
       WTPPer |      Coef.   Std. Err.      z    P>|z|     [95% Conf. Interval]
--------------+----------------------------------------------------------------
          Age |  -2.60e-14          .        .       .            .           .
       Income |  -1.73e-14          .        .       .            .           .
EducationBase |  -2.60e-13          .        .       .            .           .
    Household |   8.66e-15          .        .       .            .           .
 FishAssocMem |  -3.46e-14          .        .       .            .           .
      CommMem |          0  (omitted)
       BidAmt |   1.22e-15          .        .       .            .           .
        _cons |   6.109906          .        .       .            .           .
-------------------------------------------------------------------------------
Note: 0 failures and 218 successes completely determined.
heckman WTPPer Age Income EducationBase Household FishAssocMem CommMem BidAmt, twostep select(WTPPer = Age Income EducationBase Household 
> FishAssocMem CommMem BidAmt) rhosigma

Heckman selection model -- two-step estimates   Number of obs     =        218
(regression model with sample selection)        Censored obs      =          0
                                                Uncensored obs    =        218

                                                Wald chi2(7)      =     198.61
                                                Prob > chi2       =     0.0000

-------------------------------------------------------------------------------
              |      Coef.   Std. Err.      z    P>|z|     [95% Conf. Interval]
--------------+----------------------------------------------------------------
WTPPer        |
          Age |   .0090785   .0203176     0.45   0.655    -.0307434    .0489003
       Income |    .022491   .0152231     1.48   0.140    -.0073458    .0523277
EducationBase |   .0683711   .0396216     1.73   0.084    -.0092857    .1460279
    Household |   .0116895   .0102223     1.14   0.253    -.0083458    .0317248
 FishAssocMem |   .0082721   .0508522     0.16   0.871    -.0913963    .1079405
      CommMem |  -.0178611   .0760647    -0.23   0.814    -.1669452    .1312229
       BidAmt |  -.0245764   .0018022   -13.64   0.000    -.0281087   -.0210441
        _cons |   1.318616   .2651529     4.97   0.000     .7989256    1.838306
          Age |  -2.89e-15          .        .       .            .           .
       Income |   6.80e-16          .        .       .            .           .
EducationBase |  -1.24e-14          .        .       .            .           .
    Household |  -1.94e-16          .        .       .            .           .
 FishAssocMem |  -3.11e-15          .        .       .            .           .
      CommMem |  -1.07e-14          .        .       .            .           .
       BidAmt |   3.47e-18          .        .       .            .           .
        _cons |   6.072463          .        .       .            .           .
--------------+----------------------------------------------------------------
mills         |
       lambda |          0  (omitted)
--------------+----------------------------------------------------------------
          rho |    0.00000
        sigma |  .33375857
-------------------------------------------------------------------------------

. heckman WTPPer Age Income Household  BidAmt, twostep select(WTPPer = Age Income EducationBase Household FishAssocMem CommMem BidAmt) rhosi
> gma

Heckman selection model -- two-step estimates   Number of obs     =        218
(regression model with sample selection)        Censored obs      =          0
                                                Uncensored obs    =        218

                                                Wald chi2(4)      =     192.56
                                                Prob > chi2       =     0.0000

-------------------------------------------------------------------------------
              |      Coef.   Std. Err.      z    P>|z|     [95% Conf. Interval]
--------------+----------------------------------------------------------------
WTPPer        |
          Age |   .0024724   .0189079     0.13   0.896    -.0345863    .0395312
       Income |   .0232877    .015266     1.53   0.127     -.006633    .0532085
    Household |   .0134325   .0100786     1.33   0.183    -.0063212    .0331863
       BidAmt |  -.0242228   .0018028   -13.44   0.000    -.0277562   -.0206893
        _cons |    1.48447   .1065087    13.94   0.000     1.275717    1.693223
          Age |  -2.89e-15          .        .       .            .           .
       Income |   6.80e-16          .        .       .            .           .
EducationBase |  -1.24e-14          .        .       .            .           .
    Household |  -1.94e-16          .        .       .            .           .
 FishAssocMem |  -3.11e-15          .        .       .            .           .
      CommMem |  -1.07e-14          .        .       .            .           .
       BidAmt |   3.47e-18          .        .       .            .           .
        _cons |   6.072463          .        .       .            .           .
--------------+----------------------------------------------------------------
mills         |
       lambda |          0  (omitted)
--------------+----------------------------------------------------------------
          rho |    0.00000
        sigma |  .33620952
-------------------------------------------------------------------------------
I have unsuccessfully looked for information to help me understand this output so any help received here will be appreciated.