1. PES measures the responsiveness of quantity supplied to a change in price. -it is the mathematical relationship between ∆P and ∆Qs PES = %ΔQs %ΔP PES is always positive (there is a positive relationship between P & Qs). Price Elasticity of Supply

2. P Q Relatively Elastic Supply - a small price change causes a large change in Qs - 1 < PES Relatively Inelastic Supply -a large price change causes a small change in Qs - 0<PES <1 Elasticity of Supply refers to how quickly or easily suppliers are able to change supply in response to changes in price.

3. Price Elasticity of Supply P Q Perfectly Inelastic Supply - Regardless of price, supply does not change - PES = 0 - For agricultural products, the quantity of each harvest cannot be changed until the next season