# Regression doubt on ols estimator

I understand that beta-1 and beta-2 are parameters/OLS Estimators. But why is the variance of the error term a parameter?

• What do you assume about the variance? That will determine whether it is a parameter or not.
– whuber
Oct 22 '18 at 16:06

Also, I notice that your question has a secondary confusion. The parameters $$\beta_0$$ and $$\beta_1$$ are not the same as their corresponding OLS estimators. The parameters are unknown unobservable values, whereas the estimators are functions of the data that are used to estimate the parameters. This is another aspect of the confusion between a parameter, and the estimator that is estimating that parameter.