1 if observation used in section 2.4. for African countries, missing otherwise
1 if observation used in section 2.4. for American countries, missing otherwise
1 if observation used in section 2.4. for Asian and Oceanian countries, missing
Landlocked
Tropics (% land area)
abs(latitude of capital)/90
logTRAVEL
= log(  avbnzar9498 /( lbrforce1995/1000) )