Dear list members,

I have an unbalanced long T dataset (38 quarters), and running a fixed-effects model. I also include the lagged dependent variable variable due to the theory I am testing. Again, due to the theory I am testing I include lags from 1 to 4 of all explanatory variables. As the dynamic panel bias increases with a long T panel, I do not prefer to estimate a GMM model. When I obtain my results, I see that the signs of the coefficients of some of the explanatory variables changes in the further lags (e.g. lag 1 is significantly positive, but lag 2 is significantly negative). Therefore, it becomes confusing to comment on the relation of the explanatory variables with the dependent variable. I therefore wanted to know whether it is possible to estimate long-run coefficients for a fixed-effects model. I may be asking for something econometrically wrong, but want to hear suggestions if any?

Code:
xtreg ROA L1.ROA L(1/4).(RGDP INFL UNEM EA NPL_Gross CosttoIncome AbsoluteSize Current_Ratio NII_TA LSV), fe
Code:
Fixed-effects (within) regression               Number of obs      =       928
Group variable: bank                            Number of groups   =        29

R-sq:  within  = 0.7081                         Obs per group: min =        10
       between = 0.8980                                        avg =      32.0
       overall = 0.7636                                        max =        33

                                                F(41,858)          =     50.76
corr(u_i, Xb)  = 0.3092                         Prob > F           =    0.0000

-------------------------------------------------------------------------------
          ROA |      Coef.   Std. Err.      t    P>|t|     [95% Conf. Interval]
--------------+----------------------------------------------------------------
          ROA |
          L1. |   .7197828   .0201665    35.69   0.000     .6802014    .7593642
              |
         RGDP |
          L1. |   .0294273   .0216249     1.36   0.174    -.0130166    .0718712
          L2. |  -.0399119   .0188087    -2.12   0.034    -.0768283   -.0029954
          L3. |  -.0285918   .0243302    -1.18   0.240    -.0763455    .0191619
          L4. |  -.0026335   .0203985    -0.13   0.897    -.0426703    .0374034
              |
         INFL |
          L1. |   .0737775   .0305025     2.42   0.016     .0139092    .1336458
          L2. |  -.0086795   .0315864    -0.27   0.784    -.0706752    .0533162
          L3. |  -.0435002   .0356204    -1.22   0.222    -.1134135    .0264131
          L4. |   .0152626   .0222298     0.69   0.493    -.0283686    .0588937
              |
         UNEM |
          L1. |  -.0387789   .0534237    -0.73   0.468    -.1436353    .0660775
          L2. |   .0675899   .0431009     1.57   0.117    -.0170057    .1521854
          L3. |  -.0178881   .0403549    -0.44   0.658     -.097094    .0613177
          L4. |  -.0364572   .0404826    -0.90   0.368    -.1159138    .0429994
              |
           EA |
          L1. |   .0257591   .0125593     2.05   0.041     .0011084    .0504097
          L2. |    -.02367   .0149172    -1.59   0.113    -.0529485    .0056086
          L3. |   .0326956   .0154422     2.12   0.035     .0023868    .0630045
          L4. |  -.0297878   .0112333    -2.65   0.008    -.0518357   -.0077399
              |
    NPL_Gross |
          L1. |  -.0235523   .0094105    -2.50   0.013    -.0420226   -.0050819
          L2. |  -.0090256   .0112839    -0.80   0.424    -.0311728    .0131216
          L3. |   .0112926   .0107352     1.05   0.293    -.0097777    .0323629
          L4. |   .0132082   .0081891     1.61   0.107    -.0028648    .0292812
              |
 CosttoIncome |
          L1. |  -.0000295   .0000262    -1.12   0.261     -.000081     .000022
          L2. |  -.0000349   .0000262    -1.33   0.182    -.0000863    .0000164
          L3. |  -.0000639   .0000261    -2.45   0.014    -.0001151   -.0000127
          L4. |  -.0000105   .0000261    -0.40   0.687    -.0000617    .0000407
              |
 AbsoluteSize |
          L1. |   .0012674   .0026976     0.47   0.639    -.0040273    .0065621
          L2. |  -.0007526   .0033651    -0.22   0.823    -.0073574    .0058521
          L3. |   .0052451   .0034642     1.51   0.130    -.0015543    .0120444
          L4. |  -.0072977   .0027751    -2.63   0.009    -.0127445    -.001851
              |
Current_Ratio |
          L1. |   .0010355   .0013443     0.77   0.441     -.001603     .003674
          L2. |   .0011543   .0015619     0.74   0.460    -.0019113    .0042199
          L3. |  -.0035439   .0014725    -2.41   0.016    -.0064339   -.0006539
          L4. |   .0003214   .0003754     0.86   0.392    -.0004154    .0010583
              |
       NII_TA |
          L1. |   .0072502   .0166707     0.43   0.664      -.02547    .0399704
          L2. |  -.0198808   .0142598    -1.39   0.164    -.0478691    .0081074
          L3. |  -.0366395   .0140463    -2.61   0.009    -.0642085   -.0090704
          L4. |   .0037115   .0123751     0.30   0.764    -.0205776    .0280005
              |
          LSV |
          L1. |  -.0308357   .0146235    -2.11   0.035    -.0595377   -.0021337
          L2. |   .0056811   .0120967     0.47   0.639    -.0180615    .0294237
          L3. |  -.0206869    .013424    -1.54   0.124    -.0470346    .0056608
          L4. |  -.0003904   .0153515    -0.03   0.980    -.0305212    .0297405
              |
        _cons |   .0311564   .0149171     2.09   0.037     .0018781    .0604347
--------------+----------------------------------------------------------------
      sigma_u |  .00488001
      sigma_e |  .00940663
          rho |  .21206284   (fraction of variance due to u_i)
-------------------------------------------------------------------------------
F test that all u_i=0:     F(28, 858) =     2.29             Prob > F = 0.0002