[R] About calculation of the gravity model in R and STATA software

[S Ellison]

> As you can see, model coefficients (second column in the results table) are the
> same at least until the 4th mark (!) However, other results (columns in the
> table of results, since the third) is not the same.
> Could you explain differences in the results?

R and stata are clearly doing different things.
Look up how stata calculates its standard errors (which I note are described as '_robust_ ') and compare that with the documentation for the R function.
Without knowing anything about stata or your data set, my guess would be that R's quasibinomial family is allowing for overdispersion and stata is not.

S Ellison



*******************************************************************
This email and any attachments are confidential. Any use, copying or
disclosure other than by the intended recipient is unauthorised. If 
you have received this message in error, please notify the sender 
immediately via +44(0)20 8943 7000 or notify postmaster at lgcgroup.com 
and delete this message and any copies from your computer and network. 
LGC Limited. Registered in England 2991879. 
Registered office: Queens Road, Teddington, Middlesex, TW11 0LY, UK