Output from robreg.sas

	Output from robreg.sas	Source 0 Graphs

                        Fuel Consumption across the US                       1

Model: MODEL1
Dependent Variable: FUEL       Fuel consumption (/person)

                             Analysis of Variance

                                Sum of         Mean
       Source          DF      Squares       Square      F Value       Prob>F

       Model            4 399316.51094  99829.12774       22.706       0.0001
       Error           43 189049.96822   4396.51089
       C Total         47 588366.47917

           Root MSE      66.30619     R-square       0.6787
           Dep Mean     576.77083     Adj R-sq       0.6488
           C.V.          11.49611

                             Parameter Estimates

                      Parameter      Standard    T for H0:
     Variable  DF      Estimate         Error   Parameter=0    Prob > |T|

     INTERCEP   1    377.291146  185.54119075         2.033        0.0482
     TAX        1    -34.790149   12.97020164        -2.682        0.0103
     DRIVERS    1   1336.449357  192.29814253         6.950        0.0001
     ROAD       1     -0.002426    0.00338917        -0.716        0.4780
     INC        1     -0.066589    0.01722175        -3.867        0.0004

                   Variable
     Variable  DF     Label

     INTERCEP   1  Intercept
     TAX        1  Motor fuel tax (cents/gal.)
     DRIVERS    1  Proportion licensed drivers
     ROAD       1  Length Federal Highways (mi.)
     INC        1  Per Capita Personal income ($)

                        Fuel Consumption across the US                       2

  OBS    _SIGMA_    B0START     B1START    B2START     B3START      B4START

   1     66.3062    377.291    -34.7901    1336.45    -.0024259    -0.066589

                        Fuel Consumption across the US                       3
                            C1 Biweight Estimator

                   Non-Linear Least Squares Iterative Phase
                Dependent Variable FUEL   Method: Gauss-Newton
      Iter       B0             B1             B2          Weighted SS
                 B3             B4

         0     377.291146     -34.790149    1336.449357   41900.642832
                -0.002426      -0.066589
         1     377.291146     -34.790149    1336.449357   41900.913013
                -0.002426      -0.066589
         2     444.237287     -29.215927    1131.325511   35793.950329
                -0.001201      -0.068192
         3     475.053453     -24.160128    1016.028498   32115.697937
                -0.000285      -0.071438
         4     475.035294     -20.482154     969.510664   30679.909543
                 0.000419      -0.073317
         5     468.225466     -18.317927     952.660540   30111.765723
                 0.000865      -0.074227
         6     462.148446     -17.168231     947.279869   29873.345773
                 0.001115      -0.074620
         7     458.077682     -16.582099     945.913774   29767.529622
                 0.001247      -0.074784
         8     457.467577     -16.508371     945.880671   29755.183004
                 0.001265      -0.074801
         9     456.923448     -16.443799     945.865709   29744.480440
                 0.001280      -0.074815
        10     456.893141     -16.440264     945.865639   29743.898978
                 0.001280      -0.074816
        11     456.885616     -16.439388     945.865631   29743.754802
                 0.001281      -0.074816
        12     456.885147     -16.439333     945.865631   29743.745809
                 0.001281      -0.074816
        13     456.884912     -16.439306     945.865631   29743.741313
                 0.001281      -0.074816
        14     456.884897     -16.439304     945.865631   29743.741032
                 0.001281      -0.074816

NOTE: Convergence criterion met.

    Non-Linear Least Squares Summary Statistics     Dependent Variable FUEL

       Source                DF    Weighted SS     Weighted MS

       Regression             5   8452946.6436    1690589.3287
       Residual              43     29743.7410        691.7149
       Uncorrected Total     48   8482690.3847

       (Corrected Total)     47    139056.8362

                        Fuel Consumption across the US                       4
                            C1 Biweight Estimator

       Parameter     Estimate    Asymptotic             Asymptotic 95 %
                                 Std. Error         Confidence Interval
                                                    Lower         Upper

       B0         456.8848974  101.69947204  251.78913476   661.9806601
       B1         -16.4393039    7.26692130  -31.09439243    -1.7842154
       B2         945.8656309  110.49310000  723.03589381  1168.6953679
       B3           0.0012807    0.00191311   -0.00257749     0.0051388
       B4          -0.0748163    0.00921632   -0.09340273    -0.0562299


                        Asymptotic Correlation Matrix

  Corr            B0            B1            B2            B3            B4
  --------------------------------------------------------------------------
  B0               1  -0.742669351  -0.742524296  -0.539340671  -0.183113526
  B1    -0.742669351             1  0.2889606645  0.6614638485  -0.160350654
  B2    -0.742524296  0.2889606645             1  0.2213693289  -0.148709369
  B3    -0.539340671  0.6614638485  0.2213693289             1  -0.186600697
  B4    -0.183113526  -0.160350654  -0.148709369  -0.186600697             1

                        Fuel Consumption across the US                       5
                            C1 Biweight Estimator

 STATE   FUEL      H         R         RBIWT   _WEIGHT_   YHAT_OLS   YHAT_WLS

  AL      554   0.10891   0.48443    -32.121    0.57586    581.422    586.121
  AR      628   0.08037   0.34540     22.902    0.67698    613.867    605.098
  AZ      632   0.05699   0.55633     36.888    0.56875    644.489    595.112
  CA      524   0.08792   0.25668    -17.020    0.72803    569.438    541.020
  CO      587   0.05434   0.30170    -20.005    0.72460    662.870    607.005
  CT      457   0.22881   0.33753     22.381    0.57183    433.551    434.619
  DE      540   0.10941   0.26027     17.257    0.70858    570.240    522.743
  FL      574   0.02652   0.32857     21.786    0.72780    558.023    552.214
  GA      631   0.06465   0.39051     25.893    0.66036    612.088    605.107
  IA      635   0.06413   0.73489     48.728    0.47295    604.306    586.272
  ID      648   0.17091   0.42975    -28.495    0.56424    717.648    676.495
  IL      471   0.23048   0.09308      6.172    0.71017    442.253    464.828
  IN      580   0.03582   1.11955     74.233    0.32343    500.490    505.767
  KS      649   0.09537   0.20632     13.680    0.75550    694.979    635.320
  KY      534   0.10906   0.33505     22.216    0.66214    471.983    511.784
  LA      487   0.10415   0.59619    -39.531    0.51974    506.417    526.531
  MA      414   0.12515   0.88390    -58.608    0.37908    493.356    472.608
  MD      464   0.11270   0.52741     34.971    0.55030    415.079    429.029
  ME      541   0.09634   0.00193      0.128    0.90217    523.234    540.872
  MI      525   0.05563   0.12399     -8.221    0.84829    563.313    533.221
  MN      566   0.04408   0.56165    -37.241    0.57357    638.066    603.241
  MO      603   0.03815   0.36100     23.937    0.69793    597.497    579.063
  MS      577   0.13779   1.12016    -74.273    0.28903    651.650    651.273
  MT      704   0.03964   1.37687     91.295    0.23874    641.934    612.705
  NC      566   0.09125   0.22368     14.831    0.74724    531.918    551.169
  ND      714   0.07342   2.01397    133.539    0.09789    596.403    580.461
  NE      640   0.18745   0.00635     -0.421    0.80815    682.710    640.421
  NH      524   0.07402   0.32303    -21.419    0.69582    553.115    545.419
  NJ      467   0.11070   0.01001     -0.664    0.88173    491.506    467.664
  NM      699   0.07452   1.40399     93.093    0.22262    633.065    605.907
  NV      782   0.26598   2.64452    175.348    0.02641    713.799    606.652
  NY      344   0.28323   0.38016    -25.207    0.51094    318.733    369.207
  OH      498   0.04791   0.59196    -39.251    0.55465    550.395    537.251
  OK      644   0.08097   0.38073    -25.245    0.65477    716.824    669.245
  OR      610   0.05632   0.07393     -4.902    0.88551    670.398    614.902
  PA      464   0.06076   0.60340    -40.009    0.54108    489.025    504.009
  RI      410   0.09232   1.52861   -101.356    0.18701    532.029    511.356
  SC      577   0.06578   0.23606    -15.652    0.75969    588.649    592.652
  SD      865   0.19038   2.76961    183.642    0.02262    772.968    681.358
  TN      571   0.07816   0.04103      2.720    0.88997    566.907    568.280
  TX      640   0.31510   0.14797      9.811    0.60238    647.282    630.189
  UT      591   0.14885   0.68672     45.534    0.45150    556.968    545.466
  VA      547   0.07370   0.92937     61.623    0.38251    460.222    485.377
  VT      561   0.08475   0.14176     -9.399    0.80941    578.107    570.399
  WA      510   0.07231   0.13861     -9.191    0.82268    519.678    519.191
  WI      508   0.04330   0.64822    -42.981    0.52732    566.024    550.981
  WV      460   0.05175   0.59522    -39.467    0.55066    507.028    499.467
  WY      968   0.09972   4.68500    310.645    0.00000    733.053    657.355

                        Fuel Consumption across the US                       6
                            C1 Biweight Estimator

               Plot of _WEIGHT_*H$STATE.  Symbol used is '*'.

_WEIGHT_ |
         |
     1.0 +
         |
         |
         |                   * ME
         |         OR *   * TN  * NJ
         |            * MI
         |               * WA
     0.8 +                 * VT               * NE
         |              * SC
         |            CO NC ** KS
         |       * FL *  NH * CA* DE                 * IL
         |         * MO  ** AR
         |           GA *  * OK * KY
         |
     0.6 +                                                           * TX
         |       MN * * AZ      * AL       * ID      * CT
         |        WV * * PA     * MD
         |       WI * OH       * LA                            * NY
         |              * IA
         |                             * UT
         |
     0.4 +
         |               * VA      * MA
         |
         |        * IN
         |                           * MS
         |
         |         * MT  * NM
     0.2 +                   * RI
         |
         |
         |
         |               * ND
         |
         |                                    * SD          * NV
     0.0 +                    * WY
         |
         ---+--------+--------+--------+--------+--------+--------+--------+--
          0.00     0.05     0.10     0.15     0.20     0.25     0.30     0.35

                                        Leverage

NOTE: 1 obs hidden.

Output from robreg.sas

Fuel Consumption across the US 1

Fuel Consumption across the US 2

Fuel Consumption across the US 3 C1 Biweight Estimator

Fuel Consumption across the US 4 C1 Biweight Estimator

Fuel Consumption across the US 5 C1 Biweight Estimator

Fuel Consumption across the US 6 C1 Biweight Estimator