求指导动态面板数据GMM估计分析，步骤，具体过程，及结果分析
Favoring space over speed. To switch, type or click on mata: mata set matafavor speed, perm.
Warning: Number of instruments may be large relative to number of observations.
Warning: Two-step estimated covariance matrix of moments is singular.
  Using a generalized inverse to calculate optimal weighting matrix for two-step estimation.
  Difference-in-Sargan/Hansen statistics may be negative.

Dynamic panel-data estimation, two-step system GMM
------------------------------------------------------------------------------
Group variable: pro                             Number of obs      =       150
Time variable : year                            Number of groups   =        15
Number of instruments = 101                     Obs per group: min =        10
Wald chi2(10) =      3.05                                      avg =     10.00
Prob > chi2   =     0.980                                      max =        10
------------------------------------------------------------------------------
             |              Corrected
          AL |      Coef.   Std. Err.      z    P>|z|     [95% Conf. Interval]
-------------+----------------------------------------------------------------
         lAL |  -.2063333    1.12391    -0.18   0.854    -2.409157     1.99649
         GOV |    8.16949   16.84811     0.48   0.628    -24.85219    41.19117
      IMPORT |   1.018407   1.782187     0.57   0.568    -2.474616    4.511429
      EXPORT |  -.1662416   1.452649    -0.11   0.909    -3.013382    2.680899
         FDI |  -.5140696   1.860663    -0.28   0.782    -4.160902    3.132763
        ROAD |   10.74885   23.66755     0.45   0.650    -35.63871     57.1364
     RAILWAY |   -.446759   2.234852    -0.20   0.842    -4.826988     3.93347
         NET |   .1923369   .8691643     0.22   0.825    -1.511194    1.895868
        GOVR |  -.6494072    1.58091    -0.41   0.681    -3.747935     2.44912
        GOVF |  -.0413862    .163011    -0.25   0.800    -.3608818    .2781094
       _cons |  -113.4992   224.7315    -0.51   0.614    -553.9649    326.9665
------------------------------------------------------------------------------
Instruments for first differences equation
  GMM-type (missing=0, separate instruments for each period unless collapsed)
    L(1/10).(L.GOV L.IMPORT L.EXPORT L.FDI L.ROAD L.RAILWAY L.NET L.GOVR
    L.GOVF L.AL) collapsed
Instruments for levels equation
  Standard
    _cons
  GMM-type (missing=0, separate instruments for each period unless collapsed)
    D.(L.GOV L.IMPORT L.EXPORT L.FDI L.ROAD L.RAILWAY L.NET L.GOVR L.GOVF
    L.AL) collapsed
------------------------------------------------------------------------------
Arellano-Bond test for AR(1) in first differences: z =  -0.46  Pr > z =  0.645
Arellano-Bond test for AR(2) in first differences: z =   0.19  Pr > z =  0.850
------------------------------------------------------------------------------
Sargan test of overid. restrictions: chi2(90)   =  98.54  Prob > chi2 =  0.252
  (Not robust, but not weakened by many instruments.)
Hansen test of overid. restrictions: chi2(90)   =   1.33  Prob > chi2 =  1.000
  (Robust, but weakened by many instruments.)

Difference-in-Hansen tests of exogeneity of instrument subsets:
  GMM instruments for levels
    Hansen test excluding group:     chi2(80)   =   1.36  Prob > chi2 =  1.000
    Difference (null H = exogenous): chi2(10)   =  -0.03  Prob > chi2 =  1.00