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Published byHenry McGee Modified over 9 years ago
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Gu Yuxian Wang Weinan Beijing National Day School
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Part 1 The Simple Linear Regression Given two variables X and Y. , … are measured without an error, … are measured with error So we can let We can use the least squares estimators and the maximum likelihood estimator to estimate parameter and.
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The Least Squares Estimators Let All we need to do is to minimize Δ. Let, Solve the equation.
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The Maximum Likelihood Estimator Assume that So
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The likelihood function Compute and Solve We get
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Efficiency Analysis They are unbiased.
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Part2 Errors-in-Variables (EIV) Regression Model When the measurements for X is not accurate. There are two ways to measure errors. The orthogonal regression and the geometric mean regression.
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The Orthogonal Regression(OR) The distances between the regression line and points are To minimize Compute and solve We are supposed to get
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The Geometric Mean Regression(GMR) The area is To minimize Compute and solve we get
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Parametric Method Assume X and Y follow a bivariate normal distribution We use moment generating function (mgf) to derive the distribution of X and Y :
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Since are independent, we can separate mgf. The bivariate normal distribution that method of moment estimator(MOME)
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We get:
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Special Situation for MLE The Orthogonal Regression(OR) The Geometric Mean Regression (GMR)
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– This is when Y has no error. – This is when X has no error, so we get the same answer as our first discussion.
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Another Estimator We want to (1)occupy all la (like MLE) (2)without distributions(like (OR)&(G)) Calculate
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Let So is increasing and We get Prove 1-1 to
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Let So there is at least one root for Prove 1-1 to We have
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So there is ONLY one root for (when ) And when Then we have We can proof
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Another Estimator Again The angle Let Compute & solve We get ***
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Part3 Multiple Linear Regression The Least Squares Estimators Similar to simple linear regression: Compute We will get a group of equations:
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Assume its coefficient matrix is The solution is
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Errors-in-Variables (EIV) Regression Model(Two Variables) The Orthogonal Regression(OR) The Geometric Mean Regression(GMR1)(the volume ) The Geometric Mean Regression(GMR2)(the sum of area )
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