Why markets fail when your choices impose hidden costs on everyone else.

This walkthrough explores the economic concept of negative externalities. It explains how to identify these market failures, visualize their impact through graphing, and apply Pigouvian taxes to correct the resulting inefficiencies.

A negative externality occurs when an economic activity imposes an unintended cost on third parties. Because these costs are not reflected in the market price, the market fails to reach an efficient outcome, resulting in deadweight loss.

The material covers how to graph these market distortions and introduces the Pigouvian tax as a mechanism to internalize these costs. While the focus is on negative externalities, the framework also touches on Pigou’s approach to positive externalities.

Source: Day 1 | Negative Externalities | Externalities & Public Goods Unit Plan Walkthrough