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# st: relevance of instruments

 From donsaane dontsi To "statalist@hsphsun2.harvard.edu" Subject st: relevance of instruments Date Tue, 1 May 2012 22:27:40 +0100 (BST)

```Hi,
I run an ivreg2 regression , and I want to know if my instruments are strong. Here is the ouptut below: My question is: Is my instruments are strong because F=16.46 >10? Or there are not because Partial R2 are small?
thanks

. ivreg2 emploi c30a d30a d30b e30 g30a j30a j30c j30e l30a l30b a2 a4a a6a a7 b2a b2b b2c b5 (k30=  fin1k21 fink21),  ffirst robust
First-stage regressions
-----------------------
Summary results for first-stage regressions:
Shea
Variable      Partial R2      Partial R2       F(  2,   254)    P-value
k30             0.0149          0.0149             16.46         0.0000
NB: first-stage F-stat heteroskedasticity-robust

IV (2SLS) regression with robust standard errors
------------------------------------------------
Number of obs =      275
F( 19,   255) =     0.81
Prob > F      =   0.7000
Total (centered) SS     =  82.96736373                Centered R2   =  -0.2291
Total (uncentered) SS   =  88.98325588                Uncentered R2 =  -0.1460
Residual SS             =   101.976442                Root MSE      =      .61
------------------------------------------------------------------------------
|               Robust
emploi |      Coef.   Std. Err.      z    P>|z|     [95% Conf. Interval]
-------------+----------------------------------------------------------------
k30 |  -.3825684   .2103571    -1.82   0.069    -.7948607    .0297239
c30a |  -.0519788    .041202    -1.26   0.207    -.1327332    .0287757
d30a |    .108799   .0397846     2.73   0.006     .0308226    .1867754
d30b |   .0031931   .0348354     0.09   0.927    -.0650831    .0714693
e30 |   -.036257   .0293068    -1.24   0.216    -.0936972    .0211832
g30a |   .1152195    .058208     1.98   0.048     .0011339    .2293052
j30a |   .0429871   .0402775     1.07   0.286    -.0359552    .1219295
j30c |   .0356038   .0411333     0.87   0.387    -.0450161    .1162236
j30e |  -.0100979    .027043    -0.37   0.709    -.0631013    .0429054
l30a |  -.0212033   .0367756    -0.58   0.564    -.0932822    .0508756
l30b |   .0310033   .0326002     0.95   0.342    -.0328918    .0948985
a2 |  -.0603592   .0425782    -1.42   0.156     -.143811    .0230925
a4a |  -.0009478   .0028646    -0.33   0.741    -.0065624    .0046668
a6a |   .0933522   .0763294     1.22   0.221    -.0562506     .242955
a7 |   .1954874   .1460382     1.34   0.181    -.0907422    .4817169
b2a |   .0040452   .0023674     1.71   0.087    -.0005947    .0086851
b2b |   .0011903    .002382     0.50   0.617    -.0034784    .0058591
b2c |  -.0013251    .006618    -0.20   0.841    -.0142962    .0116459
b5 |  -.0002381   .0035678    -0.07   0.947     -.007231    .0067547
_cons |   .5296318   7.086394     0.07   0.940    -13.35945    14.41871
------------------------------------------------------------------------------
Hansen J statistic (overidentification test of all instruments):         0.418
Chi-sq(1) P-val =   0.51788
------------------------------------------------------------------------------
Instrumented:  k30
Instruments:   fin1k21 fink21 c30a d30a d30b e30 g30a j30a j30c j30e l30a l30b
a2 a4a a6a a7 b2a b2b b2c b5
------------------------------------------------------------------------------

donsaane

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