Hi all !

I'm running a bilateral trade panel data of 42 reporter with 186 partner for the year 2015 and 2017. I do have a lot of missing datas in my dataset. I am trying to assess the impact of trade facilitation measures on trade flows. lgeneraltf_ij is the geometric average of trade facilitation score of country i and j (UN global survey on trade facilitation)
I grouped the country pair so I can use the command xtreg on Stata 15.1. The Hausman test indicates that I should use a fixed effect model.

However, when I run the FE model, lots of my control variables are not significant and the R2 within is very low. I am wondering if it is because my time dimension is too restrictive (only 2 years ) and not having much variation across years. Could anyone tell me why the R2 is that low ?

In this case, should I just use the reg command and adding the fixed effect manually with dummy variables or run the between estimator with the command xtreg, y x1 x2 xn, be without taking into account the time dimension ?


Code:
estout REmodel FEmodel, cells(b(star)) stats(r2 N)

--------------------------------------------
                  REmodel         FEmodel   
                        b               b   
--------------------------------------------
lgdp_ij          .1399031***     .0211473   
lpop_ij          .0411576***     .1443081   
ldist            -.965924***            0   
lstariff         .0713956        .1930599   
contig           1.556638***            0   
comlang_off      .5072642**             0   
comcol           .2396629               0   
landlocke~ij    -2.526593***            0   
llsci_ij         .9406411***     .3432247   
lgeneralt~ij     3.731172***     1.029607   
_cons             9.73321***     5.629184***
--------------------------------------------
r2 within            .0125           .0175668   
r2 between           .6705           .3961
r2 total             .6720           .4009
N                    4088            4088   
--------------------------------------------
This is my very first time posting on the forum, I hope my query is clear enough. Thank you very much in advance to the Stata community.
Best,
Anthonin