This is my first time using the forum so apologies for any mistakes in the way I ask my question. I am running a panel data of 115 countries for 21 years (1995-2015) to look at the effect of gender inequality on GDP per capita growth. Per the literature I am lagging all of my explanatory variables by 1 year. Hausman test indicated I should use a fixed effects model. Before doing the Hausman test I had absentmindedly been running an re model which was giving me coefficients that largely agreed with the literature and mostly of high significance (particularly my main explanatory variable, l1gii). However now that I run an fe model my inequality coefficient (l1gii) is much smaller in magnitude and highly insignificant, especially the case when I include year dummies. How else might my model be misspecified?
Code:
xtreg growth l1gii l1income l1inf l1LL l1cath l1mus l1prot l1pop l1trade l1fin l1fisc l1eth l1ling l1rel l1educ i.(year), fe robust
Code:
note: l1LL omitted because of collinearity
note: l1eth omitted because of collinearity
note: l1ling omitted because of collinearity
note: l1rel omitted because of collinearity
Fixed-effects (within) regression Number of obs = 1,639
Group variable: country Number of groups = 106
R-sq: Obs per group:
within = 0.2248 min = 1
between = 0.0414 avg = 15.5
overall = 0.0006 max = 20
F(30,105) = 15.65
corr(u_i, Xb) = -0.9609 Prob > F = 0.0000
(Std. Err. adjusted for 106 clusters in country)
------------------------------------------------------------------------------
| Robust
growth | Coef. Std. Err. t P>|t| [95% Conf. Interval]
-------------+----------------------------------------------------------------
l1gii | -.4159595 3.737908 -0.11 0.912 -7.827541 6.995622
l1income | -1.860856 .5161013 -3.61 0.000 -2.884189 -.8375223
l1inf | -.0091544 .0058696 -1.56 0.122 -.0207927 .0024838
l1LL | 0 (omitted)
l1cath | .1741005 .0344523 5.05 0.000 .105788 .242413
l1mus | .188407 .1767898 1.07 0.289 -.1621346 .5389485
l1prot | .3607714 .10124 3.56 0.001 .1600311 .5615117
l1pop | 1.936552 2.402572 0.81 0.422 -2.827305 6.700408
l1trade | .0167205 .0109988 1.52 0.131 -.0050881 .038529
l1fin | -.0302813 .0148705 -2.04 0.044 -.0597668 -.0007957
l1fisc | -.0044199 .0142309 -0.31 0.757 -.0326372 .0237973
l1eth | 0 (omitted)
l1ling | 0 (omitted)
l1rel | 0 (omitted)
l1educ | .0347149 .0134619 2.58 0.011 .0080225 .0614073
|
year |
1997 | -1.020149 .5962938 -1.71 0.090 -2.202489 .1621918
1998 | -1.220308 .6580708 -1.85 0.066 -2.525141 .0845252
1999 | -1.684301 .6181221 -2.72 0.008 -2.909923 -.4586788
2000 | -1.128799 .651677 -1.73 0.086 -2.420954 .1633564
2001 | -2.095758 .5877275 -3.57 0.001 -3.261113 -.930403
2002 | -2.432149 .6708015 -3.63 0.000 -3.762224 -1.102073
2003 | -1.477883 .679521 -2.17 0.032 -2.825248 -.1305185
2004 | .351459 .6526041 0.54 0.591 -.9425344 1.645452
2005 | -.0377926 .674156 -0.06 0.955 -1.37452 1.298934
2006 | .8318328 .6862415 1.21 0.228 -.5288572 2.192523
2007 | .8639896 .7570659 1.14 0.256 -.6371321 2.365111
2008 | -.9147457 .7613802 -1.20 0.232 -2.424422 .5949306
2009 | -5.147295 .8443502 -6.10 0.000 -6.821486 -3.473105
2010 | .1432391 .8004739 0.18 0.858 -1.443953 1.730431
2011 | -.8019953 .8775833 -0.91 0.363 -2.542081 .9380903
2012 | -1.123839 .9056955 -1.24 0.217 -2.919666 .6719874
2013 | -1.283278 .9934092 -1.29 0.199 -3.253025 .6864688
2014 | -.8084123 .8947158 -0.90 0.368 -2.582468 .9656438
2015 | -.8589373 .9814056 -0.88 0.383 -2.804883 1.087009
|
_cons | -30.83163 39.49629 -0.78 0.437 -109.1455 47.48222
-------------+----------------------------------------------------------------
sigma_u | 8.3846694
sigma_e | 3.0279314
rho | .8846326 (fraction of variance due to u_i)
-------------------------------------------------------------------
Code:
xtreg growth l1gii l1income l1inf l1LL l1cath l1mus l1prot l1pop l1trade l1fin l1fisc l1eth l1ling l1rel l1educ i.(year), re robust
Code:
Random-effects GLS regression Number of obs = 1,639
Group variable: country Number of groups = 106
R-sq: Obs per group:
within = 0.2026 min = 1
between = 0.2517 avg = 15.5
overall = 0.2177 max = 20
Wald chi2(34) = 351.13
corr(u_i, X) = 0 (assumed) Prob > chi2 = 0.0000
(Std. Err. adjusted for 106 clusters in country)
------------------------------------------------------------------------------
| Robust
growth | Coef. Std. Err. z P>|z| [95% Conf. Interval]
-------------+----------------------------------------------------------------
l1gii | -5.751412 1.74489 -3.30 0.001 -9.171334 -2.331491
l1income | -1.499993 .2333249 -6.43 0.000 -1.957301 -1.042684
l1inf | -.0087819 .0061215 -1.43 0.151 -.0207798 .003216
l1LL | -.2229272 .5587782 -0.40 0.690 -1.318112 .872258
l1cath | -.002218 .0061923 -0.36 0.720 -.0143546 .0099186
l1mus | -.0030427 .0068987 -0.44 0.659 -.0165639 .0104785
l1prot | -.0023174 .0081364 -0.28 0.776 -.0182645 .0136297
l1pop | .2547697 .1420859 1.79 0.073 -.0237135 .5332529
l1trade | .0123383 .0051784 2.38 0.017 .0021888 .0224879
l1fin | -.0185212 .0125342 -1.48 0.139 -.0430878 .0060453
l1fisc | .0130483 .0098959 1.32 0.187 -.0063473 .0324439
l1eth | -.0292718 .8429514 -0.03 0.972 -1.681426 1.622883
l1ling | -.8033331 .7638123 -1.05 0.293 -2.300378 .6937115
l1rel | -.3975609 .7580992 -0.52 0.600 -1.883408 1.088286
l1educ | .0388791 .0088905 4.37 0.000 .0214541 .0563041
|
year |
1997 | -.9222909 .5993069 -1.54 0.124 -2.096911 .2523291
1998 | -1.109369 .6492041 -1.71 0.087 -2.381785 .1630481
1999 | -1.624904 .5971916 -2.72 0.007 -2.795378 -.4544303
2000 | -1.158781 .6287846 -1.84 0.065 -2.391176 .0736141
2001 | -2.084703 .5416363 -3.85 0.000 -3.146291 -1.023116
2002 | -2.489275 .6352981 -3.92 0.000 -3.734436 -1.244113
2003 | -1.678445 .6368031 -2.64 0.008 -2.926556 -.4303335
2004 | .0755202 .5863944 0.13 0.898 -1.073792 1.224832
2005 | -.3382007 .5485007 -0.62 0.538 -1.413242 .736841
2006 | .4936469 .563494 0.88 0.381 -.6107811 1.598075
2007 | .4837315 .596708 0.81 0.418 -.6857947 1.653258
2008 | -1.342811 .5740375 -2.34 0.019 -2.467904 -.2177184
2009 | -5.620564 .5967645 -9.42 0.000 -6.790201 -4.450927
2010 | -.4340173 .5686492 -0.76 0.445 -1.548549 .6805147
2011 | -1.367447 .6433871 -2.13 0.034 -2.628463 -.1064319
2012 | -1.786086 .5798817 -3.08 0.002 -2.922633 -.6495383
2013 | -2.014462 .7817502 -2.58 0.010 -3.546664 -.4822598
2014 | -1.493345 .5152251 -2.90 0.004 -2.503168 -.4835225
2015 | -1.5867 .5979239 -2.65 0.008 -2.758609 -.4147906
|
_cons | 11.0207 3.682578 2.99 0.003 3.802984 18.23842
-------------+----------------------------------------------------------------
sigma_u | 1.3768448
sigma_e | 3.0279314
rho | .17133855 (fraction of variance due to u_i)
------------------------------------------------------------------------------
Many thanks
0 Response to Insignificant and unexpected coefficients in fe model, especially with year dummies
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