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The Impact of Presidential Campaigning for Congress on Presidential Support in the U.S. House of Representatives
Paul S. Herrnson Irwin L. Morris John McTague
University of Maryland
On-Line Appendix
To further assess the possibility that our visit results are solely an artifact of selection bias, we have generated two stage least squares (2SLS) estimates for all 16 of the models in our paper. An indicator of previous presidential vote (either as a coattails measure or the actual vote percentage—as is necessary in the case of samples with freshman members) has been included as an instrument. In addition, we have estimated the following tests for each 2SLS model:
1. Two Hausman tests to evaluate the relative likelihood quality of the original OLS results and the 2SLS results. In both cases, a significant statistic suggests evidence of endogeneity—in this case a selection effect.
2. Two identification test statistics—the Anderson canonical correlation LM statistic for underidentification and the Craig-Donald Wald F statistic for weak identification. In both cases, a significant result suggests that the 2SLS model is identified (i.e. the relationship between the instrumental variable and the instruments is sufficiently strong to justify inference from the results). An insignificant test statistic indicates that the model is underidentified or too weakly identified (due to the weak relationship between the instrumental variable and the instruments) to justify inference from the model.
If a 2SLS models fails both endogeneity tests or both indentification tests, then we can have no confidence that those results are superior to the original OLS results.
In our set of 16 2SLS estimates (see below), only 6 model estimates pass the Hausmann tests (models 5-9 and 11). On the basis of this test, the OLS results are superior to the 2SLS for the remaining 10 models. If we look at the identification tests for the 6 models that passed the Hausmann tests, we see that each fails both tests. So, in those cases where the Hausmann tests suggest there might be some evidence of endogeneity, the identification tests indicate that the relationship between the instrumental variable and the instruments is so weak that no justifiable substantive conclusions can be drawn from the 2SLS results.
Given the original argument against the likelihood of significant selection bias, previous research finding no evidence of selection bias, and these new results which highlight the relative weakness
of the 2SLS results, we find no justifiable reason to question our original OLS results on the grounds that they are simply an artifact of selection bias.
Results from 16 2SLS analyses:
Key to Variable Labels
1. Presupplus1: Presidential support in the first session of 106th or 108th Congress. 2. Presupplus2: Presidential support in the second session of 106th or 108th Congress. 3. Presup: Presidential support in the year of the election (1998 or 2002). 4. Pressup_kv: Presidential support on key votes in the year indicated in the variable name. 5. Visits2_plus: Presidential visits to a member, coded 0, 1, 2, with 2 representing 2 or more visits. 6. Visitssqr: The square root of presidential visits to a member. 7. Nomdif1: The difference between the president’s ideology and the representative’s ideology in the Congress indicated in the variable name. 8. Votedif: The difference between the representative’s percentage of the vote and his/her opponent’s percentage of the vote in the election year (1998 or 2002). 9. Prescdvt: The percentage of the vote won by the president in the representative’s congressional district in the previous election (1996 or 2000). 10. Coattails: The difference between the representative’s percentage of the vote and president’s percentage of the vote in his/her district in the previous election year (1996 or 2000). 11. Seniority: The number of years the member has served in Congress.
1.. ivreg2 presupplus1 presup seniority coattails nomdif1_105 votedif (visits_2plus = votedif_1
> ) if year==1998 & win==1 & unopposed==0,
IV (2SLS) estimation
‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐
Estimates efficient for homoskedasticity only
Statistics consistent for homoskedasticity only
Number of obs = 163
F( 6, 156) = 55.62
Prob > F = 0.0000
Total (centered) SS = 19709.06748 Centered R2 = 0.6342
Total (uncentered) SS = 952553 Uncentered R2 = 0.9924
Residual SS = 7208.886292 Root MSE = 6.65
‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐
presupplus1 | Coef. Std. Err. z P>|z| [95% Conf. Interval]
‐‐‐‐‐‐‐‐‐‐‐‐‐+‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐
visits_2plus | 8.639116 10.81992 0.80 0.425 ‐12.56754 29.84577
presup | .797758 .0892388 8.94 0.000 .6228532 .9726628
seniority | ‐.0053378 .0847479 ‐0.06 0.950 ‐.1714406 .160765
coattails | .068279 .0370749 1.84 0.066 ‐.0043865 .1409445
nomdif1_105 | 3.03727 7.153562 0.42 0.671 ‐10.98345 17.05799
votedif | .0032031 .0267283 0.12 0.905 ‐.0491835 .0555897
_cons | 11.64057 7.321886 1.59 0.112 ‐2.710059 25.99121
‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐
Underidentification test (Anderson canon. corr. LM statistic): 1.143
Chi‐sq(1) P‐val = 0.2850
‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐
Weak identification test (Cragg‐Donald Wald F statistic): 1.102
Stock‐Yogo weak ID test critical values: 10% maximal IV size 16.38
15% maximal IV size 8.96
20% maximal IV size 6.66
25% maximal IV size 5.53
Source: Stock‐Yogo (2005). Reproduced by permission.
‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐
Sargan statistic (overidentification test of all instruments): 0.000
(equation exactly identified)
‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐
Instrumented: visits_2plus
Included instruments: presup seniority coattails nomdif1_105 votedif
Excluded instruments: votedif_1
‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐
. ivendog visits_2plus
Tests of endogeneity of: visits_2plus
H0: Regressor is exogenous
Wu‐Hausman F test: 0.77145 F(1,155) P‐value = 0.38113
Durbin‐Wu‐Hausman chi‐sq test: 0.80725 Chi‐sq(1) P‐value = 0.36893
2.. ivreg2 presupplus2 presup seniority coattails nomdif1_105 votedif (visits_2plus = votedif_1
> ) if year==1998 & win==1 & unopposed==0
IV (2SLS) estimation
‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐
Estimates efficient for homoskedasticity only
Statistics consistent for homoskedasticity only
Number of obs = 163
F( 6, 156) = 64.65
Prob > F = 0.0000
Total (centered) SS = 29041.84049 Centered R2 = 0.6985
Total (uncentered) SS = 991008 Uncentered R2 = 0.9912
Residual SS = 8757.104827 Root MSE = 7.33
‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐
presupplus2 | Coef. Std. Err. z P>|z| [95% Conf. Interval]
‐‐‐‐‐‐‐‐‐‐‐‐‐+‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐
visits_2plus | 6.164227 11.92532 0.52 0.605 ‐17.20898 29.53743
presup | .9541818 .0983558 9.70 0.000 .7614081 1.146956
seniority | .0848089 .0934061 0.91 0.364 ‐.0982636 .2678815
coattails | .1146408 .0408626 2.81 0.005 .0345515 .1947301
nomdif1_105 | 6.056593 7.884398 0.77 0.442 ‐9.396544 21.50973
votedif | .0609493 .029459 2.07 0.039 .0032107 .1186879
_cons | ‐1.974029 8.069919 ‐0.24 0.807 ‐17.79078 13.84272
‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐
Underidentification test (Anderson canon. corr. LM statistic): 1.143
Chi‐sq(1) P‐val = 0.2850
‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐
Weak identification test (Cragg‐Donald Wald F statistic): 1.102
Stock‐Yogo weak ID test critical values: 10% maximal IV size 16.38
15% maximal IV size 8.96
20% maximal IV size 6.66
25% maximal IV size 5.53
Source: Stock‐Yogo (2005). Reproduced by permission.
‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐
Sargan statistic (overidentification test of all instruments): 0.000
(equation exactly identified)
‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐
Instrumented: visits_2plus
Included instruments: presup seniority coattails nomdif1_105 votedif
Excluded instruments: votedif_1
‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐
. ivendog visits_2plus
Tests of endogeneity of: visits_2plus
H0: Regressor is exogenous
Wu‐Hausman F test: 0.22926 F(1,155) P‐value = 0.63274
Durbin‐Wu‐Hausman chi‐sq test: 0.24074 Chi‐sq(1) P‐value = 0.62367
3.. ivreg2 pressup_kv99 presup seniority coattails nomdif1_105 votedif (visits_2plus = votedif_
> 1) if year==1998 & win==1 & unopposed==0
IV (2SLS) estimation
‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐
Estimates efficient for homoskedasticity only
Statistics consistent for homoskedasticity only
Number of obs = 163
F( 6, 156) = 24.25
Prob > F = 0.0000
Total (centered) SS = 24536.41718 Centered R2 = 0.4776
Total (uncentered) SS = 1051639 Uncentered R2 = 0.9878
Residual SS = 12817.26236 Root MSE = 8.868
‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐
pressup_kv99 | Coef. Std. Err. z P>|z| [95% Conf. Interval]
‐‐‐‐‐‐‐‐‐‐‐‐‐+‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐
visits_2plus | 4.069504 14.42738 0.28 0.778 ‐24.20765 32.34666
presup | .8574573 .1189918 7.21 0.000 .6242375 1.090677
seniority | ‐.1538427 .1130036 ‐1.36 0.173 ‐.3753258 .0676403
coattails | .1667367 .049436 3.37 0.001 .0698438 .2636296
nomdif1_105 | 26.8588 9.538628 2.82 0.005 8.163436 45.55417
votedif | .0144718 .0356398 0.41 0.685 ‐.055381 .0843246
_cons | 10.39115 9.763073 1.06 0.287 ‐8.744121 29.52642
‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐
Underidentification test (Anderson canon. corr. LM statistic): 1.143
Chi‐sq(1) P‐val = 0.2850
‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐
Weak identification test (Cragg‐Donald Wald F statistic): 1.102
Stock‐Yogo weak ID test critical values: 10% maximal IV size 16.38
15% maximal IV size 8.96
20% maximal IV size 6.66
25% maximal IV size 5.53
Source: Stock‐Yogo (2005). Reproduced by permission.
‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐
Sargan statistic (overidentification test of all instruments): 0.000
(equation exactly identified)
‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐
Instrumented: visits_2plus
Included instruments: presup seniority coattails nomdif1_105 votedif
Excluded instruments: votedif_1
‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐
. ivendog visits_2plus
Tests of endogeneity of: visits_2plus
H0: Regressor is exogenous
Wu‐Hausman F test: 0.03088 F(1,155) P‐value = 0.86073
Durbin‐Wu‐Hausman chi‐sq test: 0.03247 Chi‐sq(1) P‐value = 0.85700
4.. ivreg2 pressup_kv00 presup seniority coattails nomdif1_105 votedif (visits_2plus = votedif_
> 1) if year==1998 & win==1 & unopposed==0
IV (2SLS) estimation
‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐
Estimates efficient for homoskedasticity only
Statistics consistent for homoskedasticity only
Number of obs = 163
F( 6, 156) = 2.34
Prob > F = 0.0342
Total (centered) SS = 38739.10429 Centered R2 = ‐0.8066
Total (uncentered) SS = 1051130 Uncentered R2 = 0.9334
Residual SS = 69987.7424 Root MSE = 20.72
‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐
pressup_kv00 | Coef. Std. Err. z P>|z| [95% Conf. Interval]
‐‐‐‐‐‐‐‐‐‐‐‐‐+‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐
visits_2plus | ‐28.2844 33.71327 ‐0.84 0.401 ‐94.3612 37.7924
presup | .8804599 .2780549 3.17 0.002 .3354824 1.425437
seniority | ‐.0249996 .2640619 ‐0.09 0.925 ‐.5425515 .4925523
coattails | .2081338 .11552 1.80 0.072 ‐.0182812 .4345488
nomdif1_105 | 35.9396 22.28945 1.61 0.107 ‐7.74691 79.62611
votedif | .0977445 .0832816 1.17 0.241 ‐.0654844 .2609734
_cons | 10.91378 22.81392 0.48 0.632 ‐33.80068 55.62824
‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐
Underidentification test (Anderson canon. corr. LM statistic): 1.143
Chi‐sq(1) P‐val = 0.2850
‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐
Weak identification test (Cragg‐Donald Wald F statistic): 1.102
Stock‐Yogo weak ID test critical values: 10% maximal IV size 16.38
15% maximal IV size 8.96
20% maximal IV size 6.66
25% maximal IV size 5.53
Source: Stock‐Yogo (2005). Reproduced by permission.
‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐
Sargan statistic (overidentification test of all instruments): 0.000
(equation exactly identified)
‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐
Instrumented: visits_2plus
Included instruments: presup seniority coattails nomdif1_105 votedif
Excluded instruments: votedif_1
‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐
. ivendog visits_2plus
Tests of endogeneity of: visits_2plus
H0: Regressor is exogenous
Wu‐Hausman F test: 1.26985 F(1,155) P‐value = 0.26154
Durbin‐Wu‐Hausman chi‐sq test: 1.32454 Chi‐sq(1) P‐value = 0.24978
5.. ivreg2 presupplus1 seniority prescdvt votedif (visits_2plus = votedif_1) if year==1998 & win
> ==1 & unopposed==0
IV (2SLS) estimation
‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐
Estimates efficient for homoskedasticity only
Statistics consistent for homoskedasticity only
Number of obs = 163
F( 4, 158) = 0.45
Prob > F = 0.7739
Total (centered) SS = 19709.06748 Centered R2 = ‐36.5463
Total (uncentered) SS = 952553 Uncentered R2 = 0.2231
Residual SS = 740002.3106 Root MSE = 67.38
‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐
presupplus1 | Coef. Std. Err. z P>|z| [95% Conf. Interval]
‐‐‐‐‐‐‐‐‐‐‐‐‐+‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐
visits_2plus | 118.4456 295.6581 0.40 0.689 ‐461.0337 697.9249
seniority | .4562806 1.37132 0.33 0.739 ‐2.231458 3.144019
prescdvt | ‐.3953329 1.996627 ‐0.20 0.843 ‐4.30865 3.517984
votedif | .1637769 .9628652 0.17 0.865 ‐1.723404 2.050958
_cons | 43.75216 75.28826 0.58 0.561 ‐103.8101 191.3144
‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐
Underidentification test (Anderson canon. corr. LM statistic): 0.159
Chi‐sq(1) P‐val = 0.6900
‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐
Weak identification test (Cragg‐Donald Wald F statistic): 0.154
Stock‐Yogo weak ID test critical values: 10% maximal IV size 16.38
15% maximal IV size 8.96
20% maximal IV size 6.66
25% maximal IV size 5.53
Source: Stock‐Yogo (2005). Reproduced by permission.
‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐
Sargan statistic (overidentification test of all instruments): 0.000
(equation exactly identified)
‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐
Instrumented: visits_2plus
Included instruments: seniority prescdvt votedif
Excluded instruments: votedif_1
‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐
. ivendog visits_2plus
Tests of endogeneity of: visits_2plus
H0: Regressor is exogenous
Wu‐Hausman F test: 9.95109 F(1,157) P‐value = 0.00193
Durbin‐Wu‐Hausman chi‐sq test: 9.71559 Chi‐sq(1) P‐value = 0.00183
6.. ivreg2 presupplus2 seniority prescdvt votedif (visits_2plus = votedif_1) if year==1998 & win
> ==1 & unopposed==0
IV (2SLS) estimation
‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐
Estimates efficient for homoskedasticity only
Statistics consistent for homoskedasticity only
Number of obs = 163
F( 4, 158) = 0.35
Prob > F = 0.8420
Total (centered) SS = 29041.84049 Centered R2 = ‐44.9777
Total (uncentered) SS = 991008 Uncentered R2 = ‐0.3474
Residual SS = 1335275.825 Root MSE = 90.51
‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐
presupplus2 | Coef. Std. Err. z P>|z| [95% Conf. Interval]
‐‐‐‐‐‐‐‐‐‐‐‐‐+‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐
visits_2plus | 158.573 397.1539 0.40 0.690 ‐619.8343 936.9803
seniority | .7015299 1.842077 0.38 0.703 ‐2.908876 4.311935
prescdvt | ‐.6148598 2.682044 ‐0.23 0.819 ‐5.871569 4.641849
votedif | .3109376 1.293405 0.24 0.810 ‐2.224089 2.845964
_cons | 31.75975 101.1338 0.31 0.753 ‐166.4588 229.9783
‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐
Underidentification test (Anderson canon. corr. LM statistic): 0.159
Chi‐sq(1) P‐val = 0.6900
‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐
Weak identification test (Cragg‐Donald Wald F statistic): 0.154
Stock‐Yogo weak ID test critical values: 10% maximal IV size 16.38
15% maximal IV size 8.96
20% maximal IV size 6.66
25% maximal IV size 5.53
Source: Stock‐Yogo (2005). Reproduced by permission.
‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐
Sargan statistic (overidentification test of all instruments): 0.000
(equation exactly identified)
‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐
Instrumented: visits_2plus
Included instruments: seniority prescdvt votedif
Excluded instruments: votedif_1
‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐
. ivendog visits_2plus
Tests of endogeneity of: visits_2plus
H0: Regressor is exogenous
Wu‐Hausman F test: 11.83903 F(1,157) P‐value = 0.00074
Durbin‐Wu‐Hausman chi‐sq test: 11.42959 Chi‐sq(1) P‐value = 0.00072
7.. ivreg2 pressup_kv99 seniority prescdvt votedif (visits_2plus = votedif_1) if year==1998 & wi
> n==1 & unopposed==0
IV (2SLS) estimation
‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐
Estimates efficient for homoskedasticity only
Statistics consistent for homoskedasticity only
Number of obs = 163
F( 4, 158) = 0.18
Prob > F = 0.9485
Total (centered) SS = 24536.41718 Centered R2 = ‐56.9682
Total (uncentered) SS = 1051639 Uncentered R2 = ‐0.3525
Residual SS = 1422331.435 Root MSE = 93.41
‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐
pressup_kv99 | Coef. Std. Err. z P>|z| [95% Conf. Interval]
‐‐‐‐‐‐‐‐‐‐‐‐‐+‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐
visits_2plus | 164.1765 409.896 0.40 0.689 ‐639.205 967.5579
seniority | .4041218 1.901178 0.21 0.832 ‐3.322119 4.130362
prescdvt | ‐.7917951 2.768094 ‐0.29 0.775 ‐6.217159 4.633569
votedif | .3257534 1.334902 0.24 0.807 ‐2.290606 2.942113
_cons | 39.9892 104.3785 0.38 0.702 ‐164.5889 244.5673
‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐
Underidentification test (Anderson canon. corr. LM statistic): 0.159
Chi‐sq(1) P‐val = 0.6900
‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐
Weak identification test (Cragg‐Donald Wald F statistic): 0.154
Stock‐Yogo weak ID test critical values: 10% maximal IV size 16.38
15% maximal IV size 8.96
20% maximal IV size 6.66
25% maximal IV size 5.53
Source: Stock‐Yogo (2005). Reproduced by permission.
‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐
Sargan statistic (overidentification test of all instruments): 0.000
(equation exactly identified)
‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐
Instrumented: visits_2plus
Included instruments: seniority prescdvt votedif
Excluded instruments: votedif_1
‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐
. ivendog visits_2plus
Tests of endogeneity of: visits_2plus
H0: Regressor is exogenous
Wu‐Hausman F test: 12.01312 F(1,157) P‐value = 0.00068
Durbin‐Wu‐Hausman chi‐sq test: 11.58572 Chi‐sq(1) P‐value = 0.00066
8. . ivreg2 pressup_kv00 seniority prescdvt votedif (visits_2plus = votedif_1) if year==1998 & wi
> n==1 & unopposed==0
IV (2SLS) estimation
‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐
Estimates efficient for homoskedasticity only
Statistics consistent for homoskedasticity only
Number of obs = 163
F( 4, 158) = 0.05
Prob > F = 0.9955
Total (centered) SS = 38739.10429 Centered R2 = ‐32.4480
Total (uncentered) SS = 1051130 Uncentered R2 = ‐0.2327
Residual SS = 1295745.219 Root MSE = 89.16
‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐
pressup_kv00 | Coef. Std. Err. z P>|z| [95% Conf. Interval]
‐‐‐‐‐‐‐‐‐‐‐‐‐+‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐
visits_2plus | 152.4572 391.2309 0.39 0.697 ‐614.3412 919.2556
seniority | .5739493 1.814605 0.32 0.752 ‐2.982612 4.13051
prescdvt | ‐.9542861 2.642045 ‐0.36 0.718 ‐6.132599 4.224027
votedif | .4717037 1.274115 0.37 0.711 ‐2.025517 2.968924
_cons | 39.20585 99.62551 0.39 0.694 ‐156.0566 234.4683
‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐
Underidentification test (Anderson canon. corr. LM statistic): 0.159
Chi‐sq(1) P‐val = 0.6900
‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐
Weak identification test (Cragg‐Donald Wald F statistic): 0.154
Stock‐Yogo weak ID test critical values: 10% maximal IV size 16.38
15% maximal IV size 8.96
20% maximal IV size 6.66
25% maximal IV size 5.53
Source: Stock‐Yogo (2005). Reproduced by permission.
‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐
Sargan statistic (overidentification test of all instruments): 0.000
(equation exactly identified)
‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐
Instrumented: visits_2plus
Included instruments: seniority prescdvt votedif
Excluded instruments: votedif_1
‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐
. ivendog visits_2plus
Tests of endogeneity of: visits_2plus
H0: Regressor is exogenous
Wu‐Hausman F test: 5.20916 F(1,157) P‐value = 0.02381
Durbin‐Wu‐Hausman chi‐sq test: 5.23456 Chi‐sq(1) P‐value = 0.02214
9.. ivreg2 presupplus1 presup seniority coattails02 nomdif1_107 votedif (visits_2plus = votedif
> _1) if year==2002 & win==1 & unopposed==0
IV (2SLS) estimation
‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐
Estimates efficient for homoskedasticity only
Statistics consistent for homoskedasticity only
Number of obs = 174
F( 6, 167) = 7.63
Prob > F = 0.0000
Total (centered) SS = 12928.85632 Centered R2 = ‐1.1189
Total (uncentered) SS = 1444193 Uncentered R2 = 0.9810
Residual SS = 27395.18497 Root MSE = 12.55
‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐
presupplus1 | Coef. Std. Err. z P>|z| [95% Conf. Interval]
‐‐‐‐‐‐‐‐‐‐‐‐‐+‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐
visits_2plus | ‐27.36594 23.09761 ‐1.18 0.236 ‐72.63642 17.90454
presup | 1.151346 .1704413 6.76 0.000 .8172871 1.485405
seniority | ‐.2398142 .2760617 ‐0.87 0.385 ‐.7808852 .3012568
coattails02 | .0348923 .058345 0.60 0.550 ‐.0794619 .1492465
nomdif1_107 | ‐1.269074 9.479611 ‐0.13 0.894 ‐19.84877 17.31062
votedif | ‐.1384608 .1595239 ‐0.87 0.385 ‐.4511219 .1742003
_cons | 4.907253 16.20612 0.30 0.762 ‐26.85615 36.67066
‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐
Underidentification test (Anderson canon. corr. LM statistic): 1.775
Chi‐sq(1) P‐val = 0.1828
‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐
Weak identification test (Cragg‐Donald Wald F statistic): 1.721
Stock‐Yogo weak ID test critical values: 10% maximal IV size 16.38
15% maximal IV size 8.96
20% maximal IV size 6.66
25% maximal IV size 5.53
Source: Stock‐Yogo (2005). Reproduced by permission.
‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐
Sargan statistic (overidentification test of all instruments): 0.000
(equation exactly identified)
‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐
Instrumented: visits_2plus
Included instruments: presup seniority coattails02 nomdif1_107 votedif
Excluded instruments: votedif_1
‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐
. ivendog visits_2plus
Tests of endogeneity of: visits_2plus
H0: Regressor is exogenous
Wu‐Hausman F test: 6.87765 F(1,166) P‐value = 0.00954
Durbin‐Wu‐Hausman chi‐sq test: 6.92230 Chi‐sq(1) P‐value = 0.00851
10.. ivreg2 presupplus2 presup seniority coattails02 nomdif1_107 votedif (visits_2plus = votedif
> _1) if year==2002 & win==1 & unopposed==0
IV (2SLS) estimation
‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐
Estimates efficient for homoskedasticity only
Statistics consistent for homoskedasticity only
Number of obs = 174
F( 6, 167) = 11.24
Prob > F = 0.0000
Total (centered) SS = 16913.42529 Centered R2 = ‐0.2444
Total (uncentered) SS = 1217260 Uncentered R2 = 0.9827
Residual SS = 21046.42264 Root MSE = 11
‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐
presupplus2 | Coef. Std. Err. z P>|z| [95% Conf. Interval]
‐‐‐‐‐‐‐‐‐‐‐‐‐+‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐
visits_2plus | ‐18.81333 20.24506 ‐0.93 0.353 ‐58.49292 20.86625
presup | 1.138356 .1493918 7.62 0.000 .8455537 1.431159
seniority | ‐.0526695 .2419681 ‐0.22 0.828 ‐.5269183 .4215794
coattails02 | .0443288 .0511394 0.87 0.386 ‐.0559026 .1445603
nomdif1_107 | 8.386265 8.308881 1.01 0.313 ‐7.898842 24.67137
votedif | ‐.036971 .1398227 ‐0.26 0.791 ‐.3110185 .2370765
_cons | ‐6.422528 14.20466 ‐0.45 0.651 ‐34.26316 21.4181
‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐
Underidentification test (Anderson canon. corr. LM statistic): 1.775
Chi‐sq(1) P‐val = 0.1828
‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐
Weak identification test (Cragg‐Donald Wald F statistic): 1.721
Stock‐Yogo weak ID test critical values: 10% maximal IV size 16.38
15% maximal IV size 8.96
20% maximal IV size 6.66
25% maximal IV size 5.53
Source: Stock‐Yogo (2005). Reproduced by permission.
‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐
Sargan statistic (overidentification test of all instruments): 0.000
(equation exactly identified)
‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐
Instrumented: visits_2plus
Included instruments: presup seniority coattails02 nomdif1_107 votedif
Excluded instruments: votedif_1
‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐
. ivendog visits_2plus
Tests of endogeneity of: visits_2plus
H0: Regressor is exogenous
Wu‐Hausman F test: 2.61894 F(1,166) P‐value = 0.10749
Durbin‐Wu‐Hausman chi‐sq test: 2.70252 Chi‐sq(1) P‐value = 0.10019
11. . ivreg2 pressup_kv03 presup seniority coattails02 nomdif1_107 votedif (visits_2plus =
votedi
> f_1) if year==2002 & win==1 & unopposed==0
IV (2SLS) estimation
Estimates efficient for homoskedasticity only
Statistics consistent for homoskedasticity only
Number of obs = 174
F( 6, 167) = 3.09
Prob > F = 0.0068
Total (centered) SS = 26062.94828 Centered R2 = ‐1.4785
Total (uncentered) SS = 1403783 Uncentered R2 = 0.9540
Residual SS = 64597.76043 Root MSE = 19.27
‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐
pressup_kv03 | Coef. Std. Err. z P>|z| [95% Conf. Interval]
‐‐‐‐‐‐‐‐‐‐‐‐‐+‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐
visits_2plus | ‐40.63201 35.46816 ‐1.15 0.252 ‐110.1483 28.8843
presup | 1.142286 .2617258 4.36 0.000 .6293131 1.655259
seniority | ‐.4450303 .423914 ‐1.05 0.294 ‐1.275887 .3858259
coattails02 | .0485509 .0895933 0.54 0.588 ‐.1270488 .2241505
nomdif1_107 | ‐12.10184 14.55667 ‐0.83 0.406 ‐40.6324 16.42871
votedif | ‐.245815 .2449612 ‐1.00 0.316 ‐.7259302 .2343002
_cons | 9.938925 24.88574 0.40 0.690 ‐38.83623 58.71408
‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐
Underidentification test (Anderson canon. corr. LM statistic): 1.775
Chi‐sq(1) P‐val = 0.1828
‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐
Weak identification test (Cragg‐Donald Wald F statistic): 1.721
Stock‐Yogo weak ID test critical values: 10% maximal IV size 16.38
15% maximal IV size 8.96
20% maximal IV size 6.66
25% maximal IV size 5.53
Source: Stock‐Yogo (2005). Reproduced by permission.
‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐
Sargan statistic (overidentification test of all instruments): 0.000
(equation exactly identified)
‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐
Instrumented: visits_2plus
Included instruments: presup seniority coattails02 nomdif1_107 votedif
Excluded instruments: votedif_1
‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐
. ivendog visits_2plus
Tests of endogeneity of: visits_2plus
H0: Regressor is exogenous
Wu‐Hausman F test: 4.10187 F(1,166) P‐value = 0.04444
Durbin‐Wu‐Hausman chi‐sq test: 4.19587 Chi‐sq(1) P‐value = 0.04052
12.. ivreg2 pressup_kv04 presup seniority coattails02 nomdif1_107 votedif (visits_2plus =
votedi
> f_1) if year==2002 & win==1 & unopposed==0
IV (2SLS) estimation
‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐
Estimates efficient for homoskedasticity only
Statistics consistent for homoskedasticity only
Number of obs = 174
F( 6, 167) = 4.69
Prob > F = 0.0002
Total (centered) SS = 30850.3046 Centered R2 = 0.1556
Total (uncentered) SS = 890043 Uncentered R2 = 0.9707
Residual SS = 26049.05363 Root MSE = 12.24
‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐
pressup_kv04 | Coef. Std. Err. z P>|z| [95% Conf. Interval]
‐‐‐‐‐‐‐‐‐‐‐‐‐+‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐
visits_2plus | 2.536693 22.52298 0.11 0.910 ‐41.60754 46.68093
presup | .7962263 .166201 4.79 0.000 .4704782 1.121974
seniority | ‐.1088406 .2691938 ‐0.40 0.686 ‐.6364507 .4187696
coattails02 | ‐.0728812 .0568935 ‐1.28 0.200 ‐.1843904 .0386281
nomdif1_107 | 7.048001 9.243775 0.76 0.446 ‐11.06947 25.16547
votedif | .0702217 .1555552 0.45 0.652 ‐.2346609 .3751044
_cons | .9632557 15.80294 0.06 0.951 ‐30.00993 31.93644
‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐
Underidentification test (Anderson canon. corr. LM statistic): 1.775
Chi‐sq(1) P‐val = 0.1828
‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐
Weak identification test (Cragg‐Donald Wald F statistic): 1.721
Stock‐Yogo weak ID test critical values: 10% maximal IV size 16.38
15% maximal IV size 8.96
20% maximal IV size 6.66
25% maximal IV size 5.53
Source: Stock‐Yogo (2005). Reproduced by permission.
‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐
Sargan statistic (overidentification test of all instruments): 0.000
(equation exactly identified)
‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐
Instrumented: visits_2plus
Included instruments: presup seniority coattails02 nomdif1_107 votedif
Excluded instruments: votedif_1
‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐
. ivendog visits_2plus
Tests of endogeneity of: visits_2plus
H0: Regressor is exogenous
Wu‐Hausman F test: 0.00458 F(1,166) P‐value = 0.94612
Durbin‐Wu‐Hausman chi‐sq test: 0.00480 Chi‐sq(1) P‐value = 0.94475
13.. ivreg2 presupplus1 seniority prescdvt votedif (visits_2plus = votedif_1) if year==2002 & win
> ==1 & unopposed==0
IV (2SLS) estimation
‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐
Estimates efficient for homoskedasticity only
Statistics consistent for homoskedasticity only
Number of obs = 174
F( 4, 169) = 1.39
Prob > F = 0.2386
Total (centered) SS = 12928.85632 Centered R2 = ‐1.3705
Total (uncentered) SS = 1444193 Uncentered R2 = 0.9788
Residual SS = 30647.85467 Root MSE = 13.27
‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐
presupplus1 | Coef. Std. Err. z P>|z| [95% Conf. Interval]
‐‐‐‐‐‐‐‐‐‐‐‐‐+‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐
visits_2plus | ‐24.67223 37.8619 ‐0.65 0.515 ‐98.8802 49.53574
seniority | ‐.218832 .3667128 ‐0.60 0.551 ‐.937576 .4999119
prescdvt | .0687865 .1659092 0.41 0.678 ‐.2563896 .3939626
votedif | ‐.140864 .2186213 ‐0.64 0.519 ‐.5693539 .2876259
_cons | 100.8083 19.61296 5.14 0.000 62.36759 139.249
‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐
Underidentification test (Anderson canon. corr. LM statistic): 0.739
Chi‐sq(1) P‐val = 0.3901
‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐
Weak identification test (Cragg‐Donald Wald F statistic): 0.720
Stock‐Yogo weak ID test critical values: 10% maximal IV size 16.38
15% maximal IV size 8.96
20% maximal IV size 6.66
25% maximal IV size 5.53
Source: Stock‐Yogo (2005). Reproduced by permission.
‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐
Sargan statistic (overidentification test of all instruments): 0.000
(equation exactly identified)
‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐
Instrumented: visits_2plus
Included instruments: seniority prescdvt votedif
Excluded instruments: votedif_1
‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐
. ivendog visits_2plus
Tests of endogeneity of: visits_2plus
H0: Regressor is exogenous
Wu‐Hausman F test: 1.12370 F(1,168) P‐value = 0.29064
Durbin‐Wu‐Hausman chi‐sq test: 1.15610 Chi‐sq(1) P‐value = 0.28227
14.. ivreg2 presupplus2 seniority prescdvt votedif (visits_2plus = votedif_1) if year==2002 & win
> ==1 & unopposed==0
IV (2SLS) estimation
‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐
Estimates efficient for homoskedasticity only
Statistics consistent for homoskedasticity only
Number of obs = 174
F( 4, 169) = 4.09
Prob > F = 0.0035
Total (centered) SS = 16913.42529 Centered R2 = ‐0.0203
Total (uncentered) SS = 1217260 Uncentered R2 = 0.9858
Residual SS = 17256.42699 Root MSE = 9.959
‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐
presupplus2 | Coef. Std. Err. z P>|z| [95% Conf. Interval]
‐‐‐‐‐‐‐‐‐‐‐‐‐+‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐
visits_2plus | ‐6.153868 28.41043 ‐0.22 0.829 ‐61.83729 49.52956
seniority | ‐.0147864 .2751703 ‐0.05 0.957 ‐.5541102 .5245374
prescdvt | .1695206 .1244933 1.36 0.173 ‐.0744818 .4135229
votedif | ‐.0011385 .1640469 ‐0.01 0.994 ‐.3226644 .3203874
_cons | 81.31047 14.71697 5.52 0.000 52.46573 110.1552
‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐
Underidentification test (Anderson canon. corr. LM statistic): 0.739
Chi‐sq(1) P‐val = 0.3901
‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐
Weak identification test (Cragg‐Donald Wald F statistic): 0.720
Stock‐Yogo weak ID test critical values: 10% maximal IV size 16.38
15% maximal IV size 8.96
20% maximal IV size 6.66
25% maximal IV size 5.53
Source: Stock‐Yogo (2005). Reproduced by permission.
‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐
Sargan statistic (overidentification test of all instruments): 0.000
(equation exactly identified)
‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐
Instrumented: visits_2plus
Included instruments: seniority prescdvt votedif
Excluded instruments: votedif_1
‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐
. ivendog visits_2plus
Tests of endogeneity of: visits_2plus
H0: Regressor is exogenous
Wu‐Hausman F test: 0.10449 F(1,168) P‐value = 0.74690
Durbin‐Wu‐Hausman chi‐sq test: 0.10816 Chi‐sq(1) P‐value = 0.74225
15.. ivreg2 pressup_kv03 seniority prescdvt votedif (visits_2plus = votedif_1) if year==2002 & wi
> n==1 & unopposed==0
IV (2SLS) estimation
‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐
Estimates efficient for homoskedasticity only
Statistics consistent for homoskedasticity only
Number of obs = 174
F( 4, 169) = 0.67
Prob > F = 0.6145
Total (centered) SS = 26062.94828 Centered R2 = ‐1.2532
Total (uncentered) SS = 1403783 Uncentered R2 = 0.9582
Residual SS = 58724.05178 Root MSE = 18.37
‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐
pressup_kv03 | Coef. Std. Err. z P>|z| [95% Conf. Interval]
‐‐‐‐‐‐‐‐‐‐‐‐‐+‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐
visits_2plus | ‐34.12588 52.40955 ‐0.65 0.515 ‐136.8467 68.59495
seniority | ‐.3322836 .5076145 ‐0.65 0.513 ‐1.32719 .6626226
prescdvt | .0282231 .2296564 0.12 0.902 ‐.4218951 .4783413
votedif | ‐.2180771 .302622 ‐0.72 0.471 ‐.8112052 .3750511
_cons | 105.3003 27.14882 3.88 0.000 52.08962 158.511
‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐
Underidentification test (Anderson canon. corr. LM statistic): 0.739
Chi‐sq(1) P‐val = 0.3901
‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐
Weak identification test (Cragg‐Donald Wald F statistic): 0.720
Stock‐Yogo weak ID test critical values: 10% maximal IV size 16.38
15% maximal IV size 8.96
20% maximal IV size 6.66
25% maximal IV size 5.53
Source: Stock‐Yogo (2005). Reproduced by permission.
‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐
Sargan statistic (overidentification test of all instruments): 0.000
(equation exactly identified)
‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐
Instrumented: visits_2plus
Included instruments: seniority prescdvt votedif
Excluded instruments: votedif_1
‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐
. ivendog visits_2plus
Tests of endogeneity of: visits_2plus
H0: Regressor is exogenous
Wu‐Hausman F test: 0.95311 F(1,168) P‐value = 0.33033
Durbin‐Wu‐Hausman chi‐sq test: 0.98158 Chi‐sq(1) P‐value = 0.32181
16.. ivreg2 pressup_kv04 seniority prescdvt votedif (visits_2plus = votedif_1) if year==2002 & wi
> n==1 & unopposed==0
IV (2SLS) estimation
‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐
Estimates efficient for homoskedasticity only
Statistics consistent for homoskedasticity only
Number of obs = 174
F( 4, 169) = 0.29
Prob > F = 0.8871
Total (centered) SS = 30850.3046 Centered R2 = ‐2.7972
Total (uncentered) SS = 890043 Uncentered R2 = 0.8684
Residual SS = 117143.4964 Root MSE = 25.95
‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐
pressup_kv04 | Coef. Std. Err. z P>|z| [95% Conf. Interval]
‐‐‐‐‐‐‐‐‐‐‐‐‐+‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐
visits_2plus | ‐50.78575 74.02212 ‐0.69 0.493 ‐195.8664 94.29494
seniority | ‐.5479211 .7169438 ‐0.76 0.445 ‐1.953105 .857263
prescdvt | ‐.18079 .3243617 ‐0.56 0.577 ‐.8165273 .4549473
votedif | ‐.2074329 .4274168 ‐0.49 0.627 ‐1.045154 .6302885
_cons | 94.07108 38.34441 2.45 0.014 18.91741 169.2248
‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐
Underidentification test (Anderson canon. corr. LM statistic): 0.739
Chi‐sq(1) P‐val = 0.3901
‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐
Weak identification test (Cragg‐Donald Wald F statistic): 0.720
Stock‐Yogo weak ID test critical values: 10% maximal IV size 16.38
15% maximal IV size 8.96
20% maximal IV size 6.66
25% maximal IV size 5.53
Source: Stock‐Yogo (2005). Reproduced by permission.
‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐
Sargan statistic (overidentification test of all instruments): 0.000
(equation exactly identified)
‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐
Instrumented: visits_2plus
Included instruments: seniority prescdvt votedif
Excluded instruments: votedif_1
‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐
. ivendog visits_2plus
Tests of endogeneity of: visits_2plus
H0: Regressor is exogenous
Wu‐Hausman F test: 2.11750 F(1,168) P‐value = 0.14749
Durbin‐Wu‐Hausman chi‐sq test: 2.16583 Chi‐sq(1) P‐value = 0.14111
