Dear all,

I have the results from xtabond2 as follows:
Code:
Dynamic panel-data estimation, two-step system GMM
------------------------------------------------------------------------------
Group variable: firmid                          Number of obs      =       370
Time variable : year                            Number of groups   =        56
Number of instruments = 40                      Obs per group: min =         2
F(28, 55)     =     17.64                                      avg =      6.61
Prob > F      =     0.000                                      max =         9
------------------------------------------------------------------------------
             |              Corrected
     lnTobin |      Coef.   Std. Err.      t    P>|t|     [95% Conf. Interval]
-------------+----------------------------------------------------------------
     lnTobin |
         L1. |   .3589312   .1495623     2.40   0.020     .0592016    .6586608
             |
       PerFD |  -1.529385   .9790586    -1.56   0.124    -3.491462    .4326921
       After |  -.2640213   .1342461    -1.97   0.054    -.5330566     .005014
     AfterFD |   2.464606   1.261673     1.95   0.056    -.0638425    4.993055
      PerInD |   .4815669   .6739103     0.71   0.478    -.8689795    1.832113
        Dual |  -.0423404   .2274878    -0.19   0.853    -.4982362    .4135553
 lnCEOtenure |    .019317   .0855446     0.23   0.822    -.1521183    .1907522
        FCEO |   .0934513   .3517923     0.27   0.792    -.6115562    .7984589
       bsize |    1.34156   .6865983     1.95   0.056    -.0344134    2.717534
       lnage |  -.0837236   .0475913    -1.76   0.084    -.1790987    .0116515
    Firmsize |  -.0796772   .0762127    -1.05   0.300    -.2324109    .0730566
        blev |   .0898659   .3326785     0.27   0.788    -.5768368    .7565685
       y2001 |   .0924929   .5832582     0.16   0.875    -1.076383    1.261369
       y2002 |  -.0795403   .3058306    -0.26   0.796    -.6924385     .533358
       y2003 |   .2306446   .1815684     1.27   0.209    -.1332266    .5945159
       y2004 |    .232103   .1600517     1.45   0.153    -.0886478    .5528537
       y2005 |   .1602183   .0964058     1.66   0.102    -.0329833    .3534199
       y2006 |   .2876385   .0717168     4.01   0.000     .1439149    .4313621
       y2007 |   .2983802   .0771674     3.87   0.000     .1437333    .4530272
       y2009 |   .2357406   .0857651     2.75   0.008     .0638634    .4076177
       y2010 |   .2821254   .0938799     3.01   0.004     .0939859     .470265
       y2011 |   .2311672   .0806831     2.87   0.006     .0694747    .3928597
       y2012 |    .326781    .086148     3.79   0.000     .1541365    .4994255
       y2013 |   .2673544   .0890159     3.00   0.004     .0889627    .4457462
       y2014 |   .2717915   .1009934     2.69   0.009     .0693961    .4741868
       y2015 |    .174857   .1158495     1.51   0.137    -.0573106    .4070246
       y2016 |   .1760335   .1125244     1.56   0.123    -.0494705    .4015376
       y2017 |   .4763668   .1463013     3.26   0.002     .1831725    .7695611
       _cons |  -1.195517   1.267733    -0.94   0.350    -3.736111    1.345076
------------------------------------------------------------------------------
Instruments for first differences equation
  Standard
    D.(After lnage 2000b.year 2001.year 2002.year 2003.year 2004.year
    2005.year 2006.year 2007.year 2008.year 2009.year 2010.year 2011.year
    2012.year 2013.year 2014.year 2015.year 2016.year 2017.year)
  GMM-type (missing=0, separate instruments for each period unless collapsed)
    L2.(AfterFD PerFD PerInD Dual lnCEOtenure FemaleCEO bsize Firmsize blev)
    collapsed
    L(2/3).lnTobin collapsed
Instruments for levels equation
  Standard
    After lnage 2000b.year 2001.year 2002.year 2003.year 2004.year 2005.year
    2006.year 2007.year 2008.year 2009.year 2010.year 2011.year 2012.year
    2013.year 2014.year 2015.year 2016.year 2017.year
    _cons
  GMM-type (missing=0, separate instruments for each period unless collapsed)
    DL.(AfterFD PerFD PerInD Dual lnCEOtenure FemaleCEO bsize Firmsize blev)
    collapsed
    DL.lnTobin collapsed
------------------------------------------------------------------------------
Arellano-Bond test for AR(1) in first differences: z =  -3.06  Pr > z =  0.002
Arellano-Bond test for AR(2) in first differences: z =  -0.60  Pr > z =  0.547
------------------------------------------------------------------------------
Sargan test of overid. restrictions: chi2(11)   =  12.16  Prob > chi2 =  0.352
  (Not robust, but not weakened by many instruments.)
Hansen test of overid. restrictions: chi2(11)   =   7.04  Prob > chi2 =  0.796
  (Robust, but weakened by many instruments.)

Difference-in-Hansen tests of exogeneity of instrument subsets:
  GMM instruments for levels
    Hansen test excluding group:     chi2(1)    =   3.88  Prob > chi2 =  0.049
    Difference (null H = exogenous): chi2(10)   =   3.16  Prob > chi2 =  0.977
  gmm(lnTobin, collapse eq(diff) lag(2 3))
    Hansen test excluding group:     chi2(9)    =   6.33  Prob > chi2 =  0.707
    Difference (null H = exogenous): chi2(2)    =   0.71  Prob > chi2 =  0.700
  gmm(lnTobin, collapse eq(diff) lag(2 3)) eq(level) lag(1 1))
    Hansen test excluding group:     chi2(10)   =   6.93  Prob > chi2 =  0.732
    Difference (null H = exogenous): chi2(1)    =   0.11  Prob > chi2 =  0.743
My interest coefficient is AfterFD. And it is significant at 10%. Also, the AR(2) is not significant and Hansen test of overid restrictions is not significant. it means my regression work through, isn't it?

In addition, could you please give me interpretation of Difference-in-Hansen test of exogeneity? As far as I understand, it should be insignificant. However, from the table, GMM instruments for levels - Hansen text excluding group: chi2(1) =3.88 Pro>chi2=0.049. Does it matter?

Thank you very much in advance.