How is the change in expected value of the outcome variable, Y, due to a change in regressor, X, measured in non-linear regression models measured? The coefficient on X, while all other regressors remain constant. Change in the value of the non-linear functional form when X changes while other regressors remain constant. The average of coefficients on all the non-linear terms of X while all other regressors remain constant. The product of the coefficient and X