Hi Martin
My data is in a panel and is organised by country pair (dyadic). it looks a 
bit like this:
biltrade    tid      cid   importer   exporter     gdpimp       gdpexp 
popimp   popexp   dist             etc
.000288  2003  1     ANG        BWA     10767.67   5795.94     4.619 
1.771      2223.578
.021651 1992   2     ANG        BDI        8023.988   847.43      10.852 
5.795     1878.576
I want to generate cids (country pair id) dummies and use them as control 
factors. I have 650 such cids which i would like to include in my 
regression.
Also, if I wanted to create a separate dataset with the same data but 
instead of country pair id dummies, I would like to have separate dummies 
for importer and exporter, how can I do this?
Many thanks for your help
Seema 
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