Season 5 Episode 8: Olly, a victim of violence from the Wildlings, asks Samuel Tarly why Jon Snow intends to help people who have been the Night’s Watch enemies for years. Samuel explains that in order to fend off against the White Walkers, Jon must have the strength of the Wilding army on his side if they want to stand a chance. Sam describes this as a trade off – receiving something desirable by giving up something you desire a little less. This is similar to marginal analysis, specifically opportunity costs, which undermines much of microeconomic thought.