Non-linearity in OLS-Models, Multinominal Logit-Regression

Hey there,

I have a question connected to the Ols-Model in case of nonlinearity between parameters. What should be done if the assummption of Linearity in OLS-Model ist not fulfilled and there is an non-linear relationship between the used parameters?

And my second question is if I can use a multinominal logit-regression in case of non-linearity between the parameters?

Thank you in advance,
Mr. Buis is surely correct. On top of that, MLR is appropriate when your DV is categorical (has nothing to do with linearity of the parameters).