Hello!

I am trying to estimate the causal effect of certain individual characteristics on the outcome "net wage". My outcome variable is not measured continuously, but in 9 intervals/bins (which are censored at the lower and upper bound):

Code:
tab Outcome

    Outcome |      Freq.     Percent        Cum.
------------+-----------------------------------
          1 |        357       13.02       13.02
          2 |        330       12.04       25.05
          3 |        455       16.59       41.65
          4 |        562       20.50       62.14
          5 |        472       17.21       79.36
          6 |        310       11.31       90.66
          7 |        192        7.00       97.67
          8 |         52        1.90       99.56
          9 |         12        0.44      100.00
------------+-----------------------------------
      Total |      2,742      100.00
I first estimated it with OLS as a baseline, then tried the command "intreg":

Code:
recode Outcome (1=.)(2=1)(3=2)(4=3)(5=4)(6=5)(7=6)(8=7)(9=8), gen(Outcome1)
(2742 differences between Outcome and Outcome1)

. recode Outcome (9=.), gen(Outcome2)
(12 differences between Outcome and Outcome2)

. intreg Outcome1 Outcome2 Treatment, vce(robust)

Fitting constant-only model:

Iteration 0:   log pseudolikelihood = -5373.7754  
Iteration 1:   log pseudolikelihood = -5336.1702  
Iteration 2:   log pseudolikelihood = -5336.0182  
Iteration 3:   log pseudolikelihood = -5336.0182  

Fitting full model:

Iteration 0:   log pseudolikelihood = -5373.2751  
Iteration 1:   log pseudolikelihood = -5335.7403  
Iteration 2:   log pseudolikelihood = -5335.5894  
Iteration 3:   log pseudolikelihood = -5335.5894  

Interval regression                             Number of obs     =      2,691
                                                   Uncensored     =          0
                                                   Left-censored  =        352
                                                   Right-censored =         12
                                                   Interval-cens. =      2,327

                                                Wald chi2(1)      =       0.82
Log pseudolikelihood = -5335.5894               Prob > chi2       =     0.3639

------------------------------------------------------------------------------
             |               Robust
             |      Coef.   Std. Err.      z    P>|z|     [95% Conf. Interval]
-------------+----------------------------------------------------------------
   Treatment |  -.0980528   .1080018    -0.91   0.364    -.3097325    .1136268
       _cons |   3.418425   .0991997    34.46   0.000     3.223997    3.612853
-------------+----------------------------------------------------------------
    /lnsigma |   .6866218   .0147144    46.66   0.000     .6577822    .7154614
-------------+----------------------------------------------------------------
       sigma |   1.986992   .0292373                      1.930506     2.04513
------------------------------------------------------------------------------

Now I'd like to estimate the regression, instrumenting for my "Treatment" variable with another variable. Is it possible to use IV with interval regression in Stata?

Thank you for any help!