Exporting country code
Importing country code
Common Language Dummy
Common Legal System Dummy
Common Religion (recoded)
Common Border Dummy
Currency Union Dummy
Log of Bilateral Distance
Free Trade Area Dummy
Log of Bilateral Trade
Colonial Ties Dummy
Islands (# of countries in pair)
Landlocked (# of countries in pair)
= 1 if positive trade, = 0 otherwise
lag of trade
importer
exporter