Hi master,

I have the following regression of panel data using fixed effects, I was wondering after a lot of search if can I add a time trend to the regression and if so how to test if is better that the present regression

Code:
Fixed-effects (within) regression               Number of obs     =        348
Group variable: j_SA                            Number of groups  =         29

R-sq:                                           Obs per group:
     within  = 0.7610                                         min =         12
     between = 0.0029                                         avg =       12.0
     overall = 0.0003                                         max =         12

                                                F(5,314)          =     199.99
corr(u_i, Xb)  = -0.7526                        Prob > F          =     0.0000

------------------------------------------------------------------------------
   l_arrival |      Coef.   Std. Err.      t    P>|t|     [95% Conf. Interval]
-------------+----------------------------------------------------------------
  l_incomepc |   .5538903   .2660921     2.08   0.038     .0303413    1.077439
     l_price |   .1738661   .0723778     2.40   0.017     .0314594    .3162728
  l_violence |   .0009841   .0217045     0.05   0.964    -.0417205    .0436887
     l_trade |   .4550106   .1074208     4.24   0.000      .243655    .6663661
 l_transport |   .2258229   .0742288     3.04   0.003     .0797742    .3718716
       _cons |  -3.003777   2.029769    -1.48   0.140    -6.997444    .9898895
-------------+----------------------------------------------------------------
     sigma_u |  1.9418083
     sigma_e |  .20554152
         rho |   .9889198   (fraction of variance due to u_i)
------------------------------------------------------------------------------
F test that all u_i=0: F(28, 314) = 200.43                   Prob > F = 0.0000