chapter  4
Simple Models: Statistical Inferences about Parameter Values
Pages 28

Although the sums of both the absolute errors and the squared errors seem to be reasonable alternatives, we decided in Chapter 3, for reasons of eﬃciency, practicality, and tradition, to deﬁne total error as the sum of the squared errors. In the simplest models, where we are estimating the single parameter β0, the choice of the sum of squared errors as the deﬁnition of error implies that the best estimate is the sample mean (as we proved in Chapter 2).