Understanding Positive Externalities in Economics | Khan Academy #177395 (License: Personal Use)

This educational illustration depicts a classic positive externality scenario: tree planting, where the social benefit (MB + XB curve) exceeds private marginal benefit. The shaded area represents the under-provision of trees in a free market, highlighting the need for subsidies or policy intervention to reach the socially optimal quantity. Annotations like “$10/tree benefit” and “nice to look at” emphasize non-market value.

Used in economics lessons on market failures and public goods; supports user intent to understand externalities visually, often embedded in articles, video thumbnails, or interactive learning modules on Khan Academy.