Chapter 4

Multiple Regression

4.1 Introduction

4.1 Introduction

4.2 A Model with Two Explanatory Variables

4.2 A Model with Two Explanatory Variables

4.2 A Model with Two Explanatory Variables

4.2 A Model with Two Explanatory Variables

4.2 A Model with Two Explanatory Variables

4.2 A Model with Two Explanatory Variables

4.2 A Model with Two Explanatory Variables

4.2 A Model with Two Explanatory Variables

4.2 A Model with Two Explanatory Variables

4.2 A Model with Two Explanatory Variables

4.5 Partial Correlations and Multiple Correlation

4.5 Partial Correlations and Multiple Correlation

4.5 Partial Correlations and Multiple Correlation

4.5 Partial Correlations and Multiple Correlation

4.5 Partial Correlations and Multiple Correlation

4.9 Omission of Relevant Variables and Inclusion of

Irrelevant Variables• Until now we have assumed that the multiple reg

ression equation we are estimating includes all the relevant explanatory variables.

• In practice, this is rarely the case.• Sometimes some relevant variables are not inclu

ded due to oversight or lack of measurements. • At other times some irrelevant variables are inclu

ded. What we would like to know is how our inferences change when these problems are present.

4.9 Omission of Relevant Variables and Inclusion of

Irrelevant Variables

4.9 Omission of Relevant Variables and Inclusion of

Irrelevant Variables

4.9 Omission of Relevant Variables and Inclusion of

Irrelevant Variables

4.9 Omission of Relevant Variables and Inclusion of

Irrelevant Variables

4.9 Omission of Relevant Variables and Inclusion of

Irrelevant Variables

4.9 Omission of Relevant Variables and Inclusion of

Irrelevant Variables

4.9 Omission of Relevant Variables and Inclusion of

Irrelevant Variables

4.9 Omission of Relevant Variables and Inclusion of

Irrelevant Variables

4.9 Omission of Relevant Variables and Inclusion of

Irrelevant Variables