// File New-Lec2-02-07-01-04.txt. Edition 7/14/2010. // Lab Specs // Window Title OLS_and_BLUE // Option (0 Normal, 1 Auto, 2 Heter, 3 X-e correlation, 4 Measurement, 5 Consistency (Is this used?) 0 // Constant List 40 60 10 50 // Coefficient List -2 6 2 2 // iListVarErrors 50 500 150 500 // iListSamples 3 250 1 5 // iListSamplesAutocorrelation 3 50 1 40 // iListSamplesMeasurement 3 50 1 5 // iListXMinima 0 10 10 0 // iListXMaxima 20 30 10 30 // strListFromCoef -1.0 4.0 .5 1.0 // strListToCoef 1.0 6.0 .5 3.0 // strListRho -.9 .9 .3 .0 // strListHeter -2.0 2.0 1.0 .0 // strListCoefXAndError -.9 .9 .3 .0 // iListXMeasErrVar 0 100 50 0 // Problem Specs // SampleSize // PauseCheckbox (-1 checked, 0 cleared) // EstType (0 Error, 1 Constant, 2 Coefficient) // ErrorVar // ConstValue // CoefValue // xMinValue // xMaxValue // ErrTermCheckbox (0 not visible and unchecked, -1 visible and checked, 1 visible and unchecked)) // VarEstAndFromTo (-1 VarEst visible, 0 nothing visible, 1 From-To visible) ` 5 0 2 500 50 2 0 30 0 1 Objective: Illustrate that the OLS estimation procedure is the best linear unbiased estimation procedure (BLUE) when the "standard" OLS regression premises are met. _ Check to be certain that the sample size is 5 and the Pause checkbox is cleared. Note that the Act Coef radiobutton is selected. _ A From value of 1.0 and a To value of 3.0 are specified. The From-To line reports the percent of repetitions in which the estimate lies within 1.0 of the actual value 2.0. ` 5 0 2 500 50 2 0 30 0 1 Focus your attention on the drop down box just above the Start button. We call this the Procedures drop down box. _ 1. By default, the OLS estimation procedure is specified. Click Start and then after many, many repetitions click Stop. _ 1a. What is the mean of the coefficient estimates? Is the ordinary least squares (OLS) estimation procedure unbiased? Explain. _ 1b. What is the variance of the coefficient estimates? In what percent of the repetitions does the estimate lie between 1.0 and 3.0? ` 5 0 2 500 50 2 0 30 0 1 2. Click on the Procedure drop down box, the box just above the Start button. Select Any Two rather than OLS. With this procedure two observations are choosen randomly. The slope of the straight line passing through the two points is used to estimate the coefficient. Click Start and then after many, many repetitions click Stop. _ 2a. What is the mean of the coefficient estimates? Is the ordinary least squares (OLS) estimation procedure unbiased? Explain. _ 2b. What is the variance of the coefficient estimates? In what percent of the repetitions does the estimate lie between 1.0 and 3.0? ` 5 0 2 500 50 2 0 30 0 1 3. Click on the Procedure drop down box, Select Min-Max estimation procedure. With this procedure the two observations with the smallest and largest values of x are choosen. The slope of the straight line passing through the two points is used to estimate the coefficient. Click Start and then after many, many repetitions click Stop. _ 3a. What is the mean of the coefficient estimates? Is the ordinary least squares (OLS) estimation procedure unbiased? Explain. _ 3b. What is the variance of the coefficient estimates? In what percent of the repetitions does the estimate lie between 1.0 and 3.0? ` 4. Compare your answers to questions 1, 2, and 3. How are the estimation procedures similar? How do they differ? Which estimation procedure is the "best?" Explain.