Unit 3: Elasticity About this unit Why are resold concert tickets so expensive? Why is holiday candy so cheap in January? Learn how supply and demand changes can influences how much things cost, and why the prices of some items can change so dramatically.

An elastic demand or elastic supply is one in which the elasticity is greater than one, indicating a high responsiveness to changes in price. An inelastic demand or inelastic supply is one in which elasticity is less than one, indicating low responsiveness to price changes.

Explore the concept of price elasticity of demand in microeconomics with Khan Academy's engaging video lesson.

In this video, take a deeper dive into the total revenue rule and the relationship between total revenue and elasticity.

An interesting case of price elasticity of demand is a demand curve with a constant unit elasticity. Explore what such a demand curve would look like in this video.

In a previous lesson we learned about price elasticity of demand, but there are many other types of elasticity that measure how agents respond to variables other than the change in a good's price.

Elasticity of demand is not the slope of the curve. The percentage part of the equation is crucial. Use the formula Sal gives and test it by yourself. On a straight line, elasticity will be highest …

Practice what you've learned about the relationship between price elasticity of demand and total revenue in this exercise.

- [Instructor] In several videos we have talked already about the price elasticity of supply. In this video, we're going to dig a little bit deeper, and we're going to think about what factors might make a supply curve, or supply schedule, or portions of it, to be more elastic or inelastic.

Practice what you've learned about income elasticity of demand in this exercise.