LEGACY CONTENT. If you are looking for Voteview.com, PLEASE CLICK HERE

This site is an archived version of Voteview.com archived from University of Georgia on May 23, 2017. This point-in-time capture includes all files publicly linked on Voteview.com at that time. We provide access to this content as a service to ensure that past users of Voteview.com have access to historical files. This content will remain online until at least January 1st, 2018. UCLA provides no warranty or guarantee of access to these files.

45-734 PROBABILITY AND STATISTICS II (4th Mini AY1997-98)

Note Set 6 Handouts



  1. KEPLER.WF1 Examples

    LS DAYS C DIST
    HIST RESID

    Note that the Probability here is 0.668929 so we do not reject the null hypothesis that residuals are normally distributed.

    SCAT(R) LOG(DAYS) LOG(DIST)

    LS LOG(DAYS) C LOG(DIST)
    ============================================================
    LS // Dependent Variable is LOG(DAYS)                                 
    Date: 04/04/98   Time: 17:18                                          
    Sample: 1 9                                                           
    Included observations: 9                                              
    ============================================================
          Variable      CoefficienStd. Errort-Statistic  Prob.            
    ============================================================
             C           5.901252   0.001346   4385.273   0.0000          
         LOG(DIST)       1.498890   0.000617   2430.848   0.0000          
    ============================================================
    R-squared            0.999999    Mean dependent var 8.081784          
    Adjusted R-squared   0.999999    S.D. dependent var 2.586347          
    S.E. of regression   0.003009    Akaike info criter-11.41893          
    Sum squared resid    6.34E-05    Schwarz criterion -11.37510          
    Log likelihood       40.61473    F-statistic        5909021.          
    Durbin-Watson stat   1.598728    Prob(F-statistic)  0.000000          
    ============================================================
    
    SCAT RESID LOG(DIST)

    Note the scale on the residuals!

    To directly test Kepler's 3rd Law:

    LS DAYS^2 C DIST^3
    ============================================================
    LS // Dependent Variable is DAYS^2                                    
    Date: 04/04/98   Time: 17:27                                          
    Sample: 1 9                                                           
    Included observations: 9                                              
    ============================================================
          Variable      CoefficienStd. Errort-Statistic  Prob.            
    ============================================================
             C           7012275.   9104212.   0.770223   0.4664          
           DIST^3        131103.7   396.1369   330.9556   0.0000          
    ============================================================
    R-squared            0.999936    Mean dependent var 1.44E+09          
    Adjusted R-squared   0.999927    S.D. dependent var 2.81E+09          
    S.E. of regression   24038144    Akaike info criter 34.18343          
    Sum squared resid    4.04E+15    Schwarz criterion  34.22726          
    Log likelihood      -164.5959    F-statistic        109531.6          
    Durbin-Watson stat   2.174360    Prob(F-statistic)  0.000000          
    ============================================================
    

  2. WINDMILL.WF1 Examples

    LS DCOUT C WIND
    ============================================================
    LS // Dependent Variable is DCOUT                                     
    Date: 04/04/98   Time: 17:30                                          
    Sample: 1 25                                                          
    Included observations: 25                                             
    ============================================================
          Variable      CoefficienStd. Errort-Statistic  Prob.            
    ============================================================
             C           0.130875   0.125989   1.038779   0.3097          
            WIND         0.241149   0.019049   12.65927   0.0000          
    ============================================================
    R-squared            0.874493    Mean dependent var 1.609600          
    Adjusted R-squared   0.869036    S.D. dependent var 0.652278          
    S.E. of regression   0.236052    Akaike info criter-2.810787          
    Sum squared resid    1.281573    Schwarz criterion -2.713277          
    Log likelihood       1.661381    F-statistic        160.2571          
    Durbin-Watson stat   0.536610    Prob(F-statistic)  0.000000          
    ============================================================
    
    SCAT RESID WIND

    Ramsey Reset Test With One Fitted Term. Note that we reject the null hypothesis that we have a linear specification (that is, the y-hat-squared variable is statistically significant).
    ============================================================
    Ramsey RESET Test:                                                    
    ============================================================
    F-statistic          63.16035    Probability        0.000000          
    Log likelihood ratio 33.83734    Probability        0.000000          
    ============================================================
                                                                          
    Test Equation:                                                        
    LS // Dependent Variable is DCOUT                                     
    Date: 04/04/98   Time: 17:33                                          
    Sample: 1 25                                                          
    Included observations: 25                                             
    ============================================================
          Variable      CoefficienStd. Errort-Statistic  Prob.            
    ============================================================
             C          -1.144670   0.173341  -6.603572   0.0000          
            WIND         0.764313   0.066569   11.48152   0.0000          
          Fitted^2      -0.655530   0.082484  -7.947349   0.0000          
    ============================================================
    R-squared            0.967577    Mean dependent var 1.609600          
    Adjusted R-squared   0.964630    S.D. dependent var 0.652278          
    S.E. of regression   0.122674    Akaike info criter-4.084281          
    Sum squared resid    0.331077    Schwarz criterion -3.938016          
    Log likelihood       18.58005    F-statistic        328.2660          
    Durbin-Watson stat   1.633283    Prob(F-statistic)  0.000000          
    ============================================================
    
    Ramsey Reset Test With Three Fitted Terms. Note that we reject the null hypothesis that we have a linear specification (that is, the (y-hat)2, (y-hat)3, and (y-hat)4 variables are jointly significant!).
    ============================================================
    Ramsey RESET Test:                                                    
    ============================================================
    F-statistic          39.22341    Probability        0.000000          
    Log likelihood ratio 48.22822    Probability        0.000000          
    ============================================================
                                                                          
    Test Equation:                                                        
    LS // Dependent Variable is DCOUT                                     
    Date: 04/04/98   Time: 17:37                                          
    Sample: 1 25                                                          
    Included observations: 25                                             
    ============================================================
          Variable      CoefficienStd. Errort-Statistic  Prob.            
    ============================================================
             C          -4.499507   1.028285  -4.375738   0.0003          
            WIND         4.052803   1.096749   3.695287   0.0014          
          Fitted^2      -13.20964   4.522482  -2.920883   0.0085          
          Fitted^3       4.820264   1.900918   2.535756   0.0197          
          Fitted^4      -0.659612   0.286779  -2.300075   0.0323          
    ============================================================
    R-squared            0.981767    Mean dependent var 1.609600          
    Adjusted R-squared   0.978120    S.D. dependent var 0.652278          
    S.E. of regression   0.096483    Akaike info criter-4.499916          
    Sum squared resid    0.186180    Schwarz criterion -4.256141          
    Log likelihood       25.77549    F-statistic        269.2287          
    Durbin-Watson stat   2.511711    Prob(F-statistic)  0.000000          
    ============================================================
    
    LS DCOUT C WIND WIND^2 WIND^3
    ============================================================
    LS // Dependent Variable is DCOUT                                     
    Date: 04/04/98   Time: 17:43                                          
    Sample: 1 25                                                          
    Included observations: 25                                             
    ============================================================
          Variable      CoefficienStd. Errort-Statistic  Prob.            
    ============================================================
             C          -2.358550   0.438464  -5.379120   0.0000          
            WIND         1.426866   0.246758   5.782440   0.0000          
           WIND^2       -0.160366   0.042056  -3.813172   0.0010          
           WIND^3        0.006458   0.002211   2.920922   0.0082          
    ============================================================
    R-squared            0.976944    Mean dependent var 1.609600          
    Adjusted R-squared   0.973650    S.D. dependent var 0.652278          
    S.E. of regression   0.105881    Akaike info criter-4.345226          
    Sum squared resid    0.235428    Schwarz criterion -4.150206          
    Log likelihood       22.84186    F-statistic        296.6100          
    Durbin-Watson stat   2.122609    Prob(F-statistic)  0.000000          
    ============================================================
    
    Here is the correct specification:
    LS DCOUT C 1/WIND
    ============================================================
    LS // Dependent Variable is DCOUT                                     
    Date: 04/04/98   Time: 17:45                                          
    Sample: 1 25                                                          
    Included observations: 25                                             
    ============================================================
          Variable      CoefficienStd. Errort-Statistic  Prob.            
    ============================================================
             C           2.978860   0.044902   66.34096   0.0000          
           1/WIND       -6.934547   0.206434  -33.59215   0.0000          
    ============================================================
    R-squared            0.980025    Mean dependent var 1.609600          
    Adjusted R-squared   0.979156    S.D. dependent var 0.652278          
    S.E. of regression   0.094171    Akaike info criter-4.648660          
    Sum squared resid    0.203970    Schwarz criterion -4.551150          
    Log likelihood       24.63479    F-statistic        1128.433          
    Durbin-Watson stat   2.269181    Prob(F-statistic)  0.000000          
    ============================================================
    
    SCAT RESID 1/WIND

    Ramsey Reset Test With One Fitted Term. Note that we do not reject the null hypothesis that we have a linear specification (that is, the y-hat-squared variable is not statistically significant).
    ============================================================
    Ramsey RESET Test:                                                    
    ============================================================
    F-statistic          0.773032    Probability        0.388784          
    Log likelihood ratio 0.863364    Probability        0.352799          
    ============================================================
                                                                          
    Test Equation:                                                        
    LS // Dependent Variable is DCOUT                                     
    Date: 04/04/98   Time: 17:49                                          
    Sample: 1 25                                                          
    Included observations: 25                                             
    ============================================================
          Variable      CoefficienStd. Errort-Statistic  Prob.            
    ============================================================
             C           2.671045   0.352996   7.566788   0.0000          
           1/WIND       -6.072507   1.002167  -6.059378   0.0000          
          Fitted^2       0.046004   0.052323   0.879222   0.3888          
    ============================================================
    R-squared            0.980703    Mean dependent var 1.609600          
    Adjusted R-squared   0.978949    S.D. dependent var 0.652278          
    S.E. of regression   0.094639    Akaike info criter-4.603194          
    Sum squared resid    0.197046    Schwarz criterion -4.456929          
    Log likelihood       25.06647    F-statistic        559.0351          
    Durbin-Watson stat   2.400475    Prob(F-statistic)  0.000000          
    ============================================================
    

  3. MPG.WF1 Examples

    LS MPG C SPEED SPEED^2
    ============================================================
    LS // Dependent Variable is MPG                                       
    Date: 04/04/98   Time: 17:52                                          
    Sample: 1 12                                                          
    Included observations: 12                                             
    ============================================================
          Variable      CoefficienStd. Errort-Statistic  Prob.            
    ============================================================
             C          -182.5821   17.67703  -10.32878   0.0000          
           SPEED         8.983214   0.761563   11.79575   0.0000          
          SPEED^2       -0.091071   0.007993  -11.39408   0.0000          
    ============================================================
    R-squared            0.947388    Mean dependent var 32.00000          
    Adjusted R-squared   0.935696    S.D. dependent var 6.809085          
    S.E. of regression   1.726658    Akaike info criter 1.304694          
    Sum squared resid    26.83214    Schwarz criterion  1.425921          
    Log likelihood      -21.85543    F-statistic        81.03174          
    Durbin-Watson stat   2.102570    Prob(F-statistic)  0.000002          
    ============================================================
    
    SCAT RESID SPEED^2

    Under View select Representation
    Estimation Command:
    =====================
    LS MPG C SPEED SPEED^2
    
    Estimation Equation:
    =====================
    MPG = C(1) + C(2)*SPEED + C(3)*(SPEED^2)
    
    Substituted Coefficients:
    =====================
    MPG = -182.58214 + 8.9832143*SPEED - 0.091071429*(SPEED^2)
    
    Under View select Coefficient Test then select Wald Test. Note that this is testing a null hypothesis that the most efficient speed is 50 mph. We do not reject this null hypothesis.
    ====================================================
    Wald Test:                                                    
    Equation: Untitled                                            
    ====================================================
    Null HypothesisC(3)=-C(2)/100                                 
    ====================================================
    F-statistic     3.068953    Probability     0.113713          
    Chi-square      3.068953    Probability     0.079801          
    ====================================================