How do you know when their is comparative advantage

Question

How do you know when their is comparative advantage

Answer 1

Usually by calculation from data table in simple tasks at school. But in real life it is empirical research which takes into account potentials of each economy, different factors such as land, climate, labor-force, education, distance, politics, traditions, natural resources, economies of scale effects, factor mobility, etc.etc.etc).

Simplest method requires to figure-out what will be the cost of one good in terms of another.