UNIVERSITY OF CALIFORNIA, LOS ANGELES
Department of Economics

Economics 143 (Cameron) - Applied Regression Analysis

Midterm Exhibits
 |_* Hypothetical data on monthly demand for cigarettes, for a random sample
 |_* of young adult smokers (18-30 years of age).  Data include:
 |_*   age = age of individual
 |_*   inc = annual before-tax income of individual
 |_*   price = typical price paid per pack for this individual
 |_*   packs = average number of packs per month consumed by the individual

 |_sample 1 30
 |_read(smokes.dat) age inc price packs
 
|_* Descriptive Statistics
 |_stat / pcor
 NAME        N    MEAN        ST. DEV      VARIANCE     MINIMUM      MAXIMUM
 AGE          30   24.300      4.3243      18.700       18.000       30.000
 INC          30   39.967      21.227      450.59      0.00000       82.000
 PRICE        30   2.1500     0.58663E-01 0.34414E-02   2.0400       2.2500
 PACKS        30   14.433      6.1691      38.058       4.9180       26.127

 
  CORRELATION MATRIX OF VARIABLES -       30 OBSERVATIONS

 AGE        1.0000
 INC       0.88253       1.0000
 PRICE    -0.22972     -0.92490E-01   1.0000
 PACKS     0.94684      0.89881     -0.19051       1.0000
              AGE          INC          PRICE        PACKS
 
|_* Regression 1
 |_ols inc packs / anova

  R-SQUARE =   0.8079     R-SQUARE ADJUSTED =   0.8010
 VARIANCE OF THE ESTIMATE-SIGMA**2 =   89.671
 STANDARD ERROR OF THE ESTIMATE-SIGMA =   9.4695
 SUM OF SQUARED ERRORS-SSE=   2510.8
 MEAN OF DEPENDENT VARIABLE =   39.967
 LOG OF THE LIKELIHOOD FUNCTION = -108.975

                      ANALYSIS OF VARIANCE - FROM MEAN
                       SS         DF             MS                 F
 REGRESSION        10556.          1.        10556.               117.722
 ERROR             2510.8         28.        89.671               P-VALUE
 TOTAL             13067.         29.        450.59                 0.000

 
 VARIABLE   ESTIMATED  STANDARD   T-RATIO        PARTIAL STANDARDIZED ELASTICITY
   NAME    COEFFICIENT   ERROR      28 DF   P-VALUE CORR. COEFFICIENT  AT MEANS
 PACKS      3.0927     0.2850       10.85     0.000 0.899     0.8988     1.1169
 CONSTANT  -4.6708      4.463      -1.047     0.304-0.194     0.0000    -0.1169
 
 
|_* Regression 2
 |_ols packs inc / anova

  R-SQUARE =   0.8079     R-SQUARE ADJUSTED =   0.8010
 VARIANCE OF THE ESTIMATE-SIGMA**2 =   7.5739
 STANDARD ERROR OF THE ESTIMATE-SIGMA =   2.7521
 SUM OF SQUARED ERRORS-SSE=   212.07
 MEAN OF DEPENDENT VARIABLE =   14.433
 LOG OF THE LIKELIHOOD FUNCTION = -71.9038

                      ANALYSIS OF VARIANCE - FROM MEAN
                       SS         DF             MS                 F
 REGRESSION        891.61          1.        891.61               117.722
 ERROR             212.07         28.        7.5739               P-VALUE
 TOTAL             1103.7         29.        38.058                 0.000

  VARIABLE   ESTIMATED  STANDARD   T-RATIO        PARTIAL STANDARDIZED ELASTICITY
   NAME    COEFFICIENT   ERROR      28 DF   P-VALUE CORR. COEFFICIENT  AT MEANS
 INC       0.26122     0.2408E-01   10.85     0.000 0.899     0.8988     0.7233
 CONSTANT   3.9934      1.085       3.679     0.001 0.571     0.0000     0.2767
 
 
|_* Regression 3
 |_ols packs inc price / anova

  R-SQUARE =   0.8195     R-SQUARE ADJUSTED =   0.8061
 VARIANCE OF THE ESTIMATE-SIGMA**2 =   7.3790
 STANDARD ERROR OF THE ESTIMATE-SIGMA =   2.7164
 SUM OF SQUARED ERRORS-SSE=   199.23
 MEAN OF DEPENDENT VARIABLE =   14.433
 LOG OF THE LIKELIHOOD FUNCTION = -70.9672

                      ANALYSIS OF VARIANCE - FROM MEAN
                       SS         DF             MS                 F
 REGRESSION        904.45          2.        452.22                61.286
 ERROR             199.23         27.        7.3790               P-VALUE
 TOTAL             1103.7         29.        38.058                 0.000

 VARIABLE   ESTIMATED  STANDARD   T-RATIO        PARTIAL STANDARDIZED ELASTICITY
   NAME    COEFFICIENT   ERROR      27 DF   P-VALUE CORR. COEFFICIENT  AT MEANS
 INC       0.25830     0.2387E-01   10.82     0.000 0.901     0.8888     0.7153
 PRICE     -11.390      8.636      -1.319     0.198-0.246    -0.1083    -1.6967
 CONSTANT   28.598      18.69       1.530     0.138 0.283     0.0000     1.9814

 
|_* Plot A1
 |_plot inc age / gnu


 
|_* Plot A2
 |_plot price age / gnu


 
|_* Regression 4
 |_ols packs age inc price / anova auxrsqr

 R-SQUARE OF AGE      ON OTHER INDEPENDENT VARIABLES =   0.8010
 R-SQUARE OF INC      ON OTHER INDEPENDENT VARIABLES =   0.7917
 R-SQUARE OF PRICE    ON OTHER INDEPENDENT VARIABLES =   0.1077
 R-SQUARE OF CONSTANT ON OTHER INDEPENDENT VARIABLES =*********

  R-SQUARE =   0.9146     R-SQUARE ADJUSTED =   0.9047
 VARIANCE OF THE ESTIMATE-SIGMA**2 =   3.6259
 STANDARD ERROR OF THE ESTIMATE-SIGMA =   1.9042
 SUM OF SQUARED ERRORS-SSE=   94.274
 MEAN OF DEPENDENT VARIABLE =   14.433
 LOG OF THE LIKELIHOOD FUNCTION = -59.7432

                      ANALYSIS OF VARIANCE - FROM MEAN
                       SS         DF             MS                 F
 REGRESSION        1009.4          3.        336.47                92.795
 ERROR             94.274         26.        3.6259               P-VALUE
 TOTAL             1103.7         29.        38.058                 0.000

 VARIABLE   ESTIMATED  STANDARD   T-RATIO        PARTIAL STANDARDIZED ELASTICITY
   NAME    COEFFICIENT   ERROR      26 DF   P-VALUE CORR. COEFFICIENT  AT MEANS
 AGE       0.98616     0.1833       5.380     0.000 0.726     0.6913     1.6603
 INC       0.83779E-01 0.3650E-01   2.295     0.030 0.410     0.2883     0.2320
 PRICE    -0.53142      6.381     -0.8328E-01 0.934-0.016    -0.0051    -0.0792
 CONSTANT  -11.736      15.09     -0.7776     0.444-0.151     0.0000    -0.8131

 
|_* Confidence Ellipse
 |_confid age inc / gnu lineonly
 USING 95% AND 90% CONFIDENCE INTERVALS

 CONFIDENCE INTERVALS BASED ON T-DISTRIBUTION WITH  26 D.F.
      - T CRITICAL VALUES =   2.056 AND   1.706
 NAME   LOWER 2.5%   LOWER 5%   COEFFICIENT   UPPER 5%   UPPER 2.5%   STD. ERROR
 AGE       0.6093      0.6735      0.98616       1.299       1.363       0.183
 INC       0.8739E-02  0.2151E-01  0.83779E-01  0.1460      0.1588       0.036
 CONFIDENCE REGION PLOT FOR age      AND inc
  USING F DISTRIBUTION WITH 2 AND   26 D.F.     F-VALUE =   3.370



 
 |_test
 |_test inc=0
 |_test price=0
 |_end
 F STATISTIC =   2.7515678     WITH    2 AND   26 D.F.  P-VALUE= 0.08242
 WALD CHI-SQUARE STATISTIC =   5.5031356     WITH    2 D.F.  P-VALUE= 0.06383
 UPPER BOUND ON P-VALUE BY CHEBYCHEV INEQUALITY = 0.36343



 
 |_test
 |_test age=0
 |_test inc=0
 |_end
 F STATISTIC =   133.66920     WITH    2 AND   26 D.F.  P-VALUE= 0.00000
 WALD CHI-SQUARE STATISTIC =   267.33840     WITH    2 D.F.  P-VALUE= 0.00000
 UPPER BOUND ON P-VALUE BY CHEBYCHEV INEQUALITY = 0.00748

 
 |_test age=1
 TEST VALUE = -0.13839E-01 STD. ERROR OF TEST VALUE  0.18329
 T STATISTIC = -0.75503962E-01 WITH   26 D.F.    P-VALUE= 0.94039
 F STATISTIC =  0.57008483E-02 WITH    1 AND   26 D.F.  P-VALUE= 0.94039
 WALD CHI-SQUARE STATISTIC =  0.57008483E-02 WITH    1 D.F.  P-VALUE= 0.93981
 UPPER BOUND ON P-VALUE BY CHEBYCHEV INEQUALITY = 1.00000

 
 |_test inc-10*age=0
 TEST VALUE =  -9.7778     STD. ERROR OF TEST VALUE   1.8655
 T STATISTIC =  -5.2415235     WITH   26 D.F.    P-VALUE= 0.00002
 F STATISTIC =   27.473568     WITH    1 AND   26 D.F.  P-VALUE= 0.00002
 WALD CHI-SQUARE STATISTIC =   27.473568     WITH    1 D.F.  P-VALUE= 0.00000
 UPPER BOUND ON P-VALUE BY CHEBYCHEV INEQUALITY = 0.03640
 
 
|_test 10*inc=age
 TEST VALUE = -0.14837     STD. ERROR OF TEST VALUE  0.53453
 T STATISTIC = -0.27756468     WITH   26 D.F.    P-VALUE= 0.78354
 F STATISTIC =  0.77042150E-01 WITH    1 AND   26 D.F.  P-VALUE= 0.78354
 WALD CHI-SQUARE STATISTIC =  0.77042150E-01 WITH    1 D.F.  P-VALUE= 0.78135
 UPPER BOUND ON P-VALUE BY CHEBYCHEV INEQUALITY = 1.00000

Updated: 11/2/98; Prepared by: Trudy Ann Cameron; Site Index