Interpretation of sign switch of marginal effect

Asked Dec 01 '18 at 23:51

Active Dec 02 '18 at 01:34

Viewed 126 times

I have calculated marginal effects for my problem. How do I interpret aswitch of the sign of the marginal effect (see plot).

For example, when I want to answer a question like the following.

Does the effect of z on y decreases if x increases?

Furthermore, I know that z has a positive effect on y.

Do I say that the effect of z on y decreases for increasing x values and becomes negative for very big values of x or what do I say. My problem is that it decreases until 0 and then the absolute value of the marginal effect increases again.

edited Dec 02 '18 at 01:34

asked Dec 01 '18 at 23:51

Jensxy

It seems that x and z has interaction on the y. How does your model model lokk like? – user158565 Dec 02 '18 at 02:56
My derive my model with glm(y ~ x + z + x*z) in R – Jensxy Dec 02 '18 at 02:59
Based on the model you fit, I still cannot understand your graph. – user158565 Dec 02 '18 at 04:13
The graph shows that the marginal effect of z on y decreases when x increases. But I do not know what to say when the marginal effect gets negative. – Jensxy Dec 02 '18 at 13:34

Interpretation of sign switch of marginal effect

0 Answers0