[Lu Westfield]

. xtset company year
       panel variable:  company (unbalanced)
        time variable:  year, 2014 to 2018, but with gaps
                delta:  1 year

. xtreg  y x1 x2 x3 x4 x5 x6 x7 x8 i.year, fe vce(robust)

Fixed-effects (within) regression               Number of obs     =        344
Group variable: company                         Number of groups  =         79

R-sq:                                           Obs per group:
     within  = 0.7422                                         min =          1
     between = 0.3895                                         avg =        4.4
     overall = 0.5404                                         max =          5

                                                F(12,78)          =      34.66
corr(u_i, Xb)  = -0.2170                        Prob > F          =     0.0000

                               (Std. Err. adjusted for 79 clusters in company)
------------------------------------------------------------------------------
             |               Robust
           y |      Coef.   Std. Err.      t    P>|t|     [95% Conf. Interval]
-------------+----------------------------------------------------------------
          x1 |   .2848077   .1970388     1.45   0.152    -.1074664    .6770817
          x2 |  -3.275013   5.070523    -0.65   0.520    -13.36965    6.819623
          x3 |  -.3970197   .3520745    -1.13   0.263    -1.097946    .3039067
          x4 |  -12.74651    3.10502    -4.11   0.000    -18.92813   -6.564889
          x5 |    1.70377   5.311331     0.32   0.749    -8.870278    12.27782
          x6 |   10.22229   .8418369    12.14   0.000     8.546325    11.89826
          x7 |  -.0026877    .007624    -0.35   0.725    -.0178658    .0124905
          x8 |  -.1610713   .2465409    -0.65   0.515    -.6518966    .3297539
             |
        year |
       2015  |   10.80228   2.416352     4.47   0.000     5.991693    15.61287
       2016  |   9.692142   4.951764     1.96   0.054    -.1660623    19.55035
       2017  |   8.934302    5.83122     1.53   0.130    -2.674764    20.54337
       2018  |   17.87215   2.731239     6.54   0.000     12.43467    23.30963
             |
       _cons |   56.81684   57.05361     1.00   0.322    -56.76818    170.4019
-------------+----------------------------------------------------------------
     sigma_u |  22.166669
     sigma_e |  12.341649
         rho |   .7633655   (fraction of variance due to u_i)
------------------------------------------------------------------------------

.

[Matthew Gidigbi]

Hello,
I need clarification on whether to use 'xtoverid' to choose between 'fe' or 're' estimation when there is a presence of heteroscedasticity in my data but no autocorrelation.
Thank you.

[Carlo Lazzaro]

Matthew:
welcome to this forum.
The issue boils down to the evidence that -hausman- does not support non-default standard errors.
Therefore, once you have invoked cluster-robust standard errors (to take heteroskedasticity and/or autocorrelation into account) you have no other choice than switching to the community-contributed module -xtoverid- to test -fe- vs. -re- (please consider that you need -re- only for the -xtoverid- test). However, being a glorious but a bit aged module, -xtoverid- does not support -fvvarlist- notation (see -xi.- prefix for a possible workaround).

[Matthew Gidigbi]

Carlo:
I have been enjoying contributions on this platform since I joined and I appreciate this clarification brought by my contribution in terms of a question.
Thanks, and Kudos to you.