Hi everyone,

currently I am investigating a regression model with nonlinear moderating effect (XZ²):

Array

The significance of b5 indicates a nonlinear moderating effect between X and Y (see Dawson 2014).

Given the significance of this effect, I am wondering if the effect can be tested using the "utest.ado" by typing the follwoing:

utest XZ XZ², fieller level(90)

Furthermore I am wondering if the turning point of the emerging curve can be calculated as follows:

di -_b[XZ]/(2 * _b[XZ²])

Can anyone help in that regard?

Best Regards
Johannes