Total sum of squares is the sum of squared deviations from the mean of y.

Sum of squared residuals is equal to total sum of squares when the variables are demeaned.

Sum of squared residuals always equals to zero .

All of the above.

The estimator is biased, we cannot use it.

The regression line will go through the origin.

We need first to re-scale it in order to run regression without a constant.

We do not need to include constant only if there is more than 1 variable in the model.

reg y x, predict residuals

First regression command, then: "predict residuals, varname"

First regression command, then: "predict varname, res"

predict y x, residuals