Slope of the regression line:

Slides:



Advertisements
Similar presentations
Kin 304 Regression Linear Regression Least Sum of Squares
Advertisements

The Simple Regression Model
Chapter 12 Simple Linear Regression
BA 275 Quantitative Business Methods
6-1 Introduction To Empirical Models 6-1 Introduction To Empirical Models.
Regression Analysis Module 3. Regression Regression is the attempt to explain the variation in a dependent variable using the variation in independent.
Linear regression models
Definition  Regression Model  Regression Equation Y i =  0 +  1 X i ^ Given a collection of paired data, the regression equation algebraically describes.
Sociology 601 Class 17: October 28, 2009 Review (linear regression) –new terms and concepts –assumptions –reading regression computer outputs Correlation.
Simple Linear Regression
Chapter 12 Simple Linear Regression
1 1 Slide © 2014 Cengage Learning. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole.
Introduction to Regression Analysis
© 2010 Pearson Prentice Hall. All rights reserved Least Squares Regression Models.
LINEAR REGRESSION: Evaluating Regression Models. Overview Standard Error of the Estimate Goodness of Fit Coefficient of Determination Regression Coefficients.
Chapter 10 Simple Regression.
Chapter 12a Simple Linear Regression
FIN357 Li1 The Simple Regression Model y =  0 +  1 x + u.
Lesson #32 Simple Linear Regression. Regression is used to model and/or predict a variable; called the dependent variable, Y; based on one or more independent.
Probability & Statistics for Engineers & Scientists, by Walpole, Myers, Myers & Ye ~ Chapter 11 Notes Class notes for ISE 201 San Jose State University.
Quantitative Business Analysis for Decision Making Simple Linear Regression.
FIN357 Li1 The Simple Regression Model y =  0 +  1 x + u.
Correlation 1. Correlation - degree to which variables are associated or covary. (Changes in the value of one tends to be associated with changes in the.
Simple Linear Regression and Correlation
1 1 Slide Simple Linear Regression Chapter 14 BA 303 – Spring 2011.
Introduction to Linear Regression and Correlation Analysis
Chapter 11 Simple Regression
Managerial Economics Demand Estimation. Scatter Diagram Regression Analysis.
Regression. Population Covariance and Correlation.
Inference for Regression Simple Linear Regression IPS Chapter 10.1 © 2009 W.H. Freeman and Company.
Summary of introduced statistical terms and concepts mean Variance & standard deviation covariance & correlation Describes/measures average conditions.
Simple Linear Regression. The term linear regression implies that  Y|x is linearly related to x by the population regression equation  Y|x =  +  x.
Chapter 6 (cont.) Difference Estimation. Recall the Regression Estimation Procedure 2.
Multiple Regression. Simple Regression in detail Y i = β o + β 1 x i + ε i Where Y => Dependent variable X => Independent variable β o => Model parameter.
The Simple Linear Regression Model: Specification and Estimation ECON 4550 Econometrics Memorial University of Newfoundland Adapted from Vera Tabakova’s.
Ch14: Linear Least Squares 14.1: INTRO: Fitting a pth-order polynomial will require finding (p+1) coefficients from the data. Thus, a straight line (p=1)
1 Simple Linear Regression and Correlation Least Squares Method The Model Estimating the Coefficients EXAMPLE 1: USED CAR SALES.
Chapter 12 Simple Linear Regression n Simple Linear Regression Model n Least Squares Method n Coefficient of Determination n Model Assumptions n Testing.
1 1 Slide The Simple Linear Regression Model n Simple Linear Regression Model y =  0 +  1 x +  n Simple Linear Regression Equation E( y ) =  0 + 
ESTIMATION METHODS We know how to calculate confidence intervals for estimates of  and  2 Now, we need procedures to calculate  and  2, themselves.
Chapter 14 Introduction to Regression Analysis. Objectives Regression Analysis Uses of Regression Analysis Method of Least Squares Difference between.
The “Big Picture” (from Heath 1995). Simple Linear Regression.
Regression and Correlation of Data Correlation: Correlation is a measure of the association between random variables, say X and Y. No assumption that one.
1 1 Slide © 2008 Thomson South-Western. All Rights Reserved Slides by JOHN LOUCKS St. Edward’s University.
Marshall University School of Medicine Department of Biochemistry and Microbiology BMS 617 Lecture 10: Comparing Models.
Inference about the slope parameter and correlation
The simple linear regression model and parameter estimation
Lecture 11: Simple Linear Regression
Regression and Correlation of Data Summary
Regression Analysis AGEC 784.
11-1 Empirical Models Many problems in engineering and science involve exploring the relationships between two or more variables. Regression analysis.
REGRESSION G&W p
Lecture #26 Thursday, November 17, 2016 Textbook: 14.1 and 14.3
Kin 304 Regression Linear Regression Least Sum of Squares
Ch12.1 Simple Linear Regression
Statistics for Business and Economics (13e)
BPK 304W Regression Linear Regression Least Sum of Squares
Econ 3790: Business and Economics Statistics
Slides by JOHN LOUCKS St. Edward’s University.
…Don’t be afraid of others, because they are bigger than you
BPK 304W Correlation.
Simple Linear Regression - Introduction
Linear Regression.
LESSON 24: INFERENCES USING REGRESSION
No notecard for this quiz!!
Review of Chapter 2 Some Basic Concepts: Sample center
Simple Linear Regression
Correlation and Regression
Simple Linear Regression
Ch 4.1 & 4.2 Two dimensions concept
Presentation transcript:

Slope of the regression line: How to estimate the best fitting line? y=a+bx+ε (Observed values of y are contaminated with random errors) Sum of Squared Errors (SSE) 1 n 1 n Slope of the regression line: Correlation coefficient * standard deviation (y) / standard deviation (x)

Properties of the estimated regression coefficients 11/11/2018 Properties of the estimated regression coefficients (1) With increasing sample size the estimated values become closer to the true parameter values of the linear function that relates y with x. (2) The variance of the observed y-values is the sum of the vaiance ‘explained by the linear model’ and the independent error variance (3) The correlation coefficient increases as the ratio between explained variance and error variance (signal–to–noise) increases

The linear regression estimation problem revisited Estimate for the regression parameter: To distinguish the true (but unknown) parameters a, b from the estimated parameters, the ‘hat’ symbol is often used.

The linear regression estimation problem revisited Estimate for the regression parameter: Here the overbars denote the mean of the samples, sx and sy are the standard deviations of the samples of x and y Slope In the next slides I assume that the data are centered and thus the mean of x and y are 0 (and the intercept is of secondary importance and one can set the intercept to 0) Intercept

The linear regression estimation problem revisited Estimate for the regression parameter: Slope

The linear regression estimation problem revisited

The linear regression estimation problem revisited Error independent of x => Covariance 0 O

The linear regression estimation problem revisited The total variance is the sum of the variance explained by x plus the independent error variance )

The linear regression estimation problem revisited The total variance is the sum of the variance explained by x plus the independent error variance