Externality refers to the economic or social impacts of an action on third parties, often overlooked in market transactions. This concept is examined through various perspectives, from John Stuart Mill’s analysis of trade advantages based on comparative advantage to William Graham Sumner’s observations on industrial changes and their national consequences.
The Chautauqua Institution critiques the negative effects of middlemen in commerce, while George Webb Medley connects trade imbalances to a nation’s position as a creditor or debtor. These viewpoints collectively highlight externality as a complex phenomenon, where economic choices create effects that extend beyond immediate participants, influencing interconnected systems of production and exchange.