[R] Ordered probit model -marginal effects and relative importance of each predictor-

[franco salerno]

Hi, I have a problem with the ordered probit model -polr function
(library MASS). My independent variables are countinuos.
I am not able to understand two main points:

a) how to calculate marginal effects
b) how to calculate the relative importance of each independent variables

If required i will attach my model output.

Thanks

Franco