Hi all,

I've found an inverted u-shaped relation between the dependet variable "roa" and the variable of my main interest "varx".
For doing that, I used the following code:

Code:
    reg     roa2013             ///    Dependent variable
        varx2013            ///     Variable of main interest
        varxsq2013            ///     Variable of main interest squared
                        //    Controls
        controla2013            ///
        controlb2013             ///
        controlc2013            ///
        controld2013            ///
        controle2013            ///
        controlf2013                

    *Utest command
        utest varx2013 varxsq2013
Now, I would like to include a potential moderator of this relationship. I am not sure whether that is completely right but I do that by:

Code:
    reg     roa2013             ///    Dependent variable
        c.varx2013##c.varx2013##c.moderator            ///     Variable of main interest
                        //    Controls
        controla2013            ///
        controlb2013             ///
        controlc2013            ///
        controld2013            ///
        controle2013            ///
        controlf2013

The interaction varx2013##c.moderator as well as varx2013##varx2013##c.moderator (and the quadatic term) is significant.

I have now two questions:

1) Because of the fvvarlist-operators I'm using in the second regression, I cannot take advantage of the utest command anymore. Is there another way to test the significance of the inverted u-shaped relation and it's moderator (incl. turning point)?

2) How can I scatter the two u-shapes (with and without moderator) in one graph?


Code:
* Example generated by -dataex-. To install: ssc install dataex
clear
input float roa2013 double varx2013 float(moderator controlb2013 controlc2013 controld2013 controle2013 controlf2013 controlg2013)
  .05226809   5 5.666667  18.14469    .06278002 4065218.5   .3193709 1     .061403
   .0553228   4        5  14.84563    .06730169 319434.25  .54305065 1   .05809223
  .08281977 5.5        5 10.947507    .11188485 4836470.5   .8503829 0   .09462444
  .11069837   4        2  12.29784    .09459518  29807718    .900606 0   .05524298
   .0805665 5.5        5 11.919324     .1036812 1741782.6   .6284503 1   .05541043
  .11150632   7        6  10.62099    .10003947 1741782.6   .6284503 1   .05541043
  .09160694 2.5        6 10.154166     .1723896   5872063   .3670754 0 .0001397046
 -.13085464   4        6   8.91211   .033733662 3748229.5   .7868435 0 -.016308693
  .05229507 5.5        4 12.829374   .063645296  29807718    .900606 0   .05524298
 .029555695 2.5        5 17.536222   .020356985  976984.8 .007668674 .   .04100607
  .02923595 5.5        5 17.217607    .05679471 1224742.6  .04854649 1  .033227947
 -.18810207 5.5        3 16.669004    -.3212181  47613800   .7451095 1   .05309721
 .016424885 2.5        6 10.947678     .2246402 4065218.5   .3193709 0     .061403
   .1704918 5.5      5.5 12.142302     .2218278  35624924   .3757325 1  .064520545
  .03112654 5.5        7 13.287418   .071752846 4836470.5   .8503829 1   .09462444
  .04407731   7        7 12.174742    .07259794  35624924   .3757325 1  .064520545