What is an elasticity? 1:00 Price elasticity of demand 6:55 What determines how elastic demand is? 8:53 Calculating the percent change in something 23:01 The midpoint method 25:28 Calculating the price elasticity of demand 27:51 - Example 1 29:28 - Example 2 32:51 Interpretation of price elasticity of demand - what does the number mean? 44:40