PPML estimation

[Shikha Gupta]

Joao Santos Silva
Dear Joao Santos Silva
I am very new to gravity model , your kind suggestion on the model and results would help me a lot

ppml Xijt gi gj logpij lognij exchange linder3 Cost RTA contig lang Landlocked

note: checking the existence of the estimates
WARNING: Xijt has very large values, consider rescaling
WARNING: gi has very large values, consider rescaling or recentering
WARNING: gj has very large values, consider rescaling or recentering
WARNING: exchange has very large values, consider rescaling or recentering
WARNING: Cost has very large values, consider rescaling or recentering
note: starting ppml estimation
note: Xijt has noninteger values

Iteration 1: deviance = 3.93e+09
Iteration 2: deviance = 3.12e+09
Iteration 3: deviance = 3.03e+09
Iteration 4: deviance = 3.00e+09
Iteration 5: deviance = 2.91e+09
Iteration 6: deviance = 2.86e+09
Iteration 7: deviance = 2.86e+09
Iteration 8: deviance = 2.86e+09
Iteration 9: deviance = 2.86e+09
Iteration 10: deviance = 2.86e+09
Iteration 11: deviance = 2.86e+09
Iteration 12: deviance = 2.86e+09
Iteration 13: deviance = 2.86e+09
Iteration 14: deviance = 2.86e+09
Iteration 15: deviance = 2.86e+09
Iteration 16: deviance = 2.86e+09
Iteration 17: deviance = 2.86e+09
Iteration 18: deviance = 2.86e+09
Iteration 19: deviance = 2.86e+09
Iteration 20: deviance = 2.86e+09

Number of parameters: 12
Number of observations: 3922
Number of observations dropped: 0
Pseudo log-likelihood: -1.449e+09
R-squared: .58449951
------------------------------------------------------------------------------
| Robust
Xijt | Coef. Std. Err. z P>|z| [95% Conf. Interval]
-------------+----------------------------------------------------------------
gi | .0452378 .0037543 12.05 0.000 .0378794 .0525962
gj | -.0087716 .0037564 -2.34 0.020 -.016134 -.0014093
logpij | -.7586275 .1582948 -4.79 0.000 -1.06888 -.4483754
lognij | 1.95404 .13085 14.93 0.000 1.697579 2.210502
exchange | .0006345 .0004417 1.44 0.151 -.0002312 .0015003
linder3 | -.2784518 .1139317 -2.44 0.015 -.5017539 -.0551497
Cost | -.4860289 .1373231 -3.54 0.000 -.7551772 -.2168805
RTA | .5449323 .0897372 6.07 0.000 .3690506 .7208139
contig | .6506576 .1505984 4.32 0.000 .3554902 .945825
lang | .1742402 .0724501 2.40 0.016 .0322406 .3162399
Landlocked | -.6947127 .1333741 -5.21 0.000 -.9561212 -.4333043
_cons | -2.561144 .5722439 -4.48 0.000 -3.682722 -1.439567
------------------------------------------------------------------------------
Number of regressors dropped to ensure that the estimates exist: 0
Option strict is off

[Shikha Gupta]

Dear Statalisters, kindly share your opinion

[Joao Santos Silva]

Dear Shikha Gupta,

To get any meaningful responses, you need to explain what you want to do and ask specific questions.

Best wishes,

Joao

[Shikha Gupta]

Dear Joao Santos Silva sir and Statalisters
I am trying to arrest the impact of globalisation on exports.
Exports are my dependent variable and I have not taken it in log form.
The variables - Globalisation Index, Exchange rate and shipping cost are not in log form
However, I have taken the product of GDP and Product of population in log form.
Am I right in my approach?
secondly, the results say Iteration: deviance, which I am unable to interpret.
Will be grateful if you can suggest

[Joao Santos Silva]

Dear Shikha Gupta,

I suggest that you start by reading the documentation on the glm command and the references therein.

Best wishes,

Joao

[Shikha Gupta]

Dear Joao Santos Silva sir,
Thank you for your recommendation.
Shall look at it and get back
Regards
Shikha Gupta