PPML with cross sectional data

[Marlous Muis]

Dear all,
I want to run a gravity model on a cross sectional dataset. I have 30.000 bilateral observation for the year 2015 and eight independent variables ( GDP/capita, Contiguity, Common language, Common colonizer, Colony, Weighted distance, EPI, GATT, Free trade area).The dependent variable is the trade between country pairs. 80% of the dependent variable has the value zero. My idea is to use the PPML estimation. Since I am new with STATA I would like to ask for some advice to run such estimation in STATA. I am using STATA 14. Thanks in advance.

[Joao Santos Silva]

Please check the ppml command available from SSC; see also the help file.

Best wishes,

Joao

[Marlous Muis]

Thank you for the useful answer. I have an additional question to run my model. I want to run the ppml with net trade values. For example, China exports 38237 ton of waste to Hong Kong but on the other side, Hong Kong exports 1514555 ton of waste to China, I want to run my data set with the net value of this exports. What is the best way to do this?

Thanks in advance.

[Joao Santos Silva]

That is not a gravity model; I am afraid I have no suggestions.

Best wishes,

Joao