Understanding the Law of Supply

This lesson explores the Law of Supply: as the price of a good rises, the quantity supplied rises, and as the price falls, the quantity supplied falls, other things being equal. The graph shows a linear supply curve, P = 2Q, where Price is on the vertical axis and Quantity is on the horizontal axis.

How to Use the Playground

• Drag the dot along the supply curve to change Price and Quantity together.
• Use the number fields, slider, or +/− buttons (on mobile) — Price and Quantity always stay linked by the equation.
• Observe how a higher price leads to a larger quantity supplied, while a lower price leads to a smaller quantity supplied.
• Experiment with different prices to better understand the positive relationship between Price and Quantity Supplied.