title: Marginal effect of interaction variable in probit regression using Stata
body: <p>I am running a probit regression with an interaction between one continuous and one dummy variable. The coefficient is displayed in the regression output but when I look at the marginal effects the interaction is missing.</p>
  
  <p>How can I get the marginal effect of the interaction variable?</p>
  
  <pre><code>probit move_right c.real_income_change_percent##i.gender
  
  Iteration 0:   log likelihood = -345.57292  
  Iteration 1:   log likelihood = -339.10962  
  Iteration 2:   log likelihood = -339.10565  
  Iteration 3:   log likelihood = -339.10565  
  
  Probit regression                                 Number of obs   =        958
                                                    LR chi2(3)      =      12.93
                                                    Prob &gt; chi2     =     0.0048
  Log likelihood = -339.10565                       Pseudo R2       =     0.0187
  
  -----------------------------------------------------------------------------------------------------
                           move_right |      Coef.   Std. Err.      z    P&gt;|z|     [95% Conf. Interval]
  ------------------------------------+----------------------------------------------------------------
           real_income_change_percent |   .0034604   .0010125     3.42   0.001      .001476    .0054448
                                      |
                               gender |
                              Female  |   .0695646   .1139538     0.61   0.542    -.1537807    .2929099
                                      |
  gender#c.real_income_change_percent |
                              Female  |  -.0039908   .0015254    -2.62   0.009    -.0069805   -.0010011
                                      |
                                _cons |  -1.263463   .0798439   -15.82   0.000    -1.419954   -1.106972
  -----------------------------------------------------------------------------------------------------
  
  
  margins, dydx(*) post
  
  Average marginal effects                          Number of obs   =        958
  Model VCE    : OIM
  
  Expression   : Pr(move_right), predict()
  dy/dx w.r.t. : real_income_change_percent 1.gender
  
  --------------------------------------------------------------------------------------------
                             |            Delta-method
                             |      dy/dx   Std. Err.      z    P&gt;|z|     [95% Conf. Interval]
  ---------------------------+----------------------------------------------------------------
  real_income_change_percent |   .0002846   .0001454     1.96   0.050    -4.15e-07    .0005697
                             |
                      gender |
                     Female  |  -.0102626   .0207666    -0.49   0.621    -.0509643    .0304392
  --------------------------------------------------------------------------------------------
  Note: dy/dx for factor levels is the discrete change from the base level.
  </code></pre>