Simple differences for the weeks when the quarterbacks play and for which the data was used in the regression. .67 is about 10 percent bigger than .61.
. sum PercPosWeek if QBRating~=.& black==1
Variable | Obs Mean Std. Dev. Min Max
. sum PercPosWeek if QBRating~=.& black==0
Variable | Obs Mean Std. Dev. Min Max
.
Simple differences for all weeks for all quarterbacks. .641 is about 6 percent bigger than .604.
. sum PercPosWeek if black==1
Variable | Obs Mean Std. Dev. Min Max
. sum PercPosWeek if black==0
Variable | Obs Mean Std. Dev. Min Max
xi:tobit PercPosWeek
black QBRating PointsFor PointsAgainst
-------------+-----------------------------------------------------
PercPosWeek | 27 .6688732 .342553 0 1
-------------+-----------------------------------------------------
PercPosWeek | 94 .609209 .308406 0 1
-------------+-----------------------------------------------------
PercPosWeek | 32 .6408842 .3497214 0 1
-------------+-----------------------------------------------------
PercPosWeek | 105 .6043981 .3254384 0 1
TeamRankQ TeamRankOpp Win
MondayNight i.Team i.
> Opp i.week [weight= totalarticles], ll(0) ul(1)
i.Team
_ITeam_1-32 (_ITeam_1 for
Team==Arizona
Cardinals omitted)
i.Opp
_IOpp_1-32 (_IOpp_1 for
Opp==49ers omitted)
i.week
_Iweek_1-4 (naturally
coded; _Iweek_1
omitted)
(sum of wgt is
1.2550e+03)
Tobit estimates
Number of obs =
121
LR chi2(73)
=
205.44
Prob > chi2
=
0.0000
Log likelihood =
28.003807
Pseudo R2 =
1.3748
------------------------------------------------------------------------
------
PercPosWeek | Coef. Std. Err. t P>|t| [95% Conf.
Interval]
-------------
+----------------------------------------------------------------
black | .2734481 .1230312 2.22 0.031 .0260773
5208189
QBRating | .0042778
.0008661
4.94 0.000 .0025363
0060192
PointsFor |
.0072689 .0032618 2.23 0.031 .0007106
0138271
PointsAgai~t |
-.0020012
.0029544
-0.68 0.501 -.0079415
0039392
TeamRankQ | -.0058854 .0065581 -0.90 0.374 -.0190714
0073005
TeamRankOpp | -.004066 .007148 -0.57 0.572 -.018438
010306
Win | .0689655 .0919386 0.75 0.457 -.1158894
2538204
MondayNight | -.1166789 .0833576 -1.40 0.168 -.2842805
0509227
_ITeam_2 | -.0169536 .2364126 -0.07 0.943 -.4922929
4583857
_ITeam_3 |
.1468985
.2247611
0.65 0.517 -.3050141
598811
_ITeam_4 |
.0590208
.2638495
0.22 0.824 -.4714843
5895258
_ITeam_5 |
.2911653 .2525969 1.15 0.255 -.2167147
7990454
_ITeam_6 | -.2161553 .1443362 -1.50 0.141 -.5063628
0740522
_ITeam_7 | -.0661163 .2162633 -0.31 0.761 -.5009428
3687103
_ITeam_8 |
.0932468
.178421
0.52 0.604 -.2654926
4519863
_ITeam_9 |
.1050138
.2171662
0.48 0.631 -.331628
5416557
_ITeam_10 | -.2823277 .2376989 -1.19 0.241 -.7602532
1955979
_ITeam_11 |
.359611 .1958441 1.84 0.073 -.0341599
7533819
_ITeam_12 | -.0074013 .2058051 -0.04 0.971 -.4212002
4063977
_ITeam_13 |
.4754337
.2759911
1.72 0.091 -.0794837
1.030351
_ITeam_14 |
.0808871
.283296
0.29 0.776 -.4887176
6504918
_ITeam_15 |
.3843743
.2027622
1.90 0.064 -.0233064
792055
_ITeam_16 |
.2189283
.3260661
0.67 0.505 -.4366715
8745281
_ITeam_17 |
.0510487 .2493494 0.20 0.839 -.4503018
5523992
_ITeam_18 | -.1620874 .1790236 -0.91 0.370 -.5220385
1978636
_ITeam_19 | -.0875933 .2474661 -0.35 0.725 -.5851573
4099707
_ITeam_20 |
.2584589
.2356544
1.10 0.278 -.215356
7322738
_ITeam_21 |
.1647717
.2508232
0.66 0.514 -.3395422
6690855
_ITeam_22 |
.1413777
.2110102
0.67 0.506 -.2828868
5656423
_ITeam_23 | -.0462282 .2398099 -0.19 0.848 -.5283984
4359419
_ITeam_24 | -.2840534 .2414943 -1.18 0.245 -.7696102
2015033
_ITeam_25 | -.0165402 .2408452 -0.07 0.946 -.500792
4677115
_ITeam_26 |
.1426732
.2219679
0.64 0.523 -.3036232
5889695
_ITeam_27 |
.1884081
.21688
0.87 0.389 -.2476584
6244745
_ITeam_28 |
.0425871
.2651447
0.16 0.873 -.4905221
5756963
_ITeam_29 | -.0025363 .1998481 -0.01 0.990 -.4043579
3992853
_ITeam_30
| .4496921 .3139653 1.43 0.159 -.1815774
1.080962
_ITeam_31 |
3.178043 .
.
.
.
.
_ITeam_32 |
.7378628
.2546022
2.90 0.006 .2259508
1.249775
_IOpp_2 | -.1007541 .1825479 -0.55 0.584 -.4677914
2662831
_IOpp_3 | -.0297692 .1709137 -0.17 0.862 -.3734142
3138757
_IOpp_4 |
.0550556
.160173
0.34 0.733 -.2669939
3771051
_IOpp_5 |
-.085646 .1836689 -0.47 0.643 -.4549372
2836451
_IOpp_6 | -.1962476 .1604031 -1.22 0.227 -.5187596
1262643
_IOpp_7 | -.0238396 .2136971 -0.11 0.912 -.4535064
4058272
_IOpp_8 | -.0122369 .1932033 -0.06 0.950 -.4006982
3762244
_IOpp_9 | -.0388672 .1770849 -0.22 0.827 -.3949202
3171859
_IOpp_10 | -.1880141 .2046311 -0.92 0.363 -.5994525
2234244
_IOpp_11 |
-.376153
.1733265 -2.17 0.035 -.7246493
-.0276568
_IOpp_12 |
.1436151
.2033257
0.71 0.483 -.2651985
5524288
_IOpp_13 |
.0507561
.1905883
0.27 0.791 -.3324475
4339596
_IOpp_14 | -.2776187 .1953781 -1.42 0.162 -.6704526
1152153
_IOpp_15 | -.5578314 .1784203 -3.13 0.003 -.9165694
-.1990934
_IOpp_16 | -.1151433 .1257375 -0.92 0.364 -.3679554
1376689
_IOpp_17 | -.1094862 .2057352 -0.53 0.597 -.5231446
3041721
_IOpp_18 | -.0544749 .2030736 -0.27 0.790 -.4627817
3538319
_IOpp_19 |
.2291882
.1330673
1.72 0.091 -.0383615
4967378
_IOpp_20 | -.1222153 .1203123 -1.02 0.315 -.3641195
1196888
_IOpp_21 | -.2180942 .2131641 -1.02 0.311 -.6466894
210501
_IOpp_22 | -.1832558 .1774323 -1.03 0.307 -.5400074
1734957
_IOpp_23 |
.0881241
.173308
0.51 0.613 -.2603349
4365831
_IOpp_24 |
.1699097
.1528968
1.11 0.272 -.13751
4773294
_IOpp_25 | -.1035977 .1459429 -0.71 0.481 -.3970355
18984
_IOpp_26 | -.0699196 .1842127 -0.38 0.706 -.440304
3004648
_IOpp_27 |
.2282577
.2903517
0.79 0.436 -.3555336
812049
_IOpp_28 |
.2051037
.1628612
1.26 0.214 -.1223507
532558
_IOpp_29 |
-.37455 .1787284 -2.10 0.041 -.7339076
-.0151924
_IOpp_30
| -.2430252 .23099 -1.05 0.298 -.7074618
2214113
_IOpp_31 | -.1823366 .1934259 -0.94 0.351 -.5712454
2065723
_IOpp_32 | -.1796585 .1135712 -1.58 0.120 -.4080087
0486917
_Iweek_2 | -.0568646 .041737 -1.36 0.179 -.1407824
0270532
_Iweek_3 | -.0334785 .0472319 -0.71 0.482 -.1284445
0614875
_Iweek_4 | -.1143263 .0509259 -2.24 0.029 -.2167196
-.011933
_cons | .2993115 .3220289 0.93 0.357 -.348171
9467941
-------------
+----------------------------------------------------------------
_se | .1335311 .0106433
(Ancillary parameter)
------------------------------------------------------------------------
------
Obs.
summary: 5 left-censored observations at
PercPo~k<=0
87 uncensored
observations
29 right-censored observations at PercPo~k>=1