2.1.6—Supply curve shifts

A supply shift means firms offer a different quantity at every price because production conditions changed. Technology, input costs, taxes, subsidies, weather, firm numbers and expectations are common causes.

A right shift represents greater supply at each price; a left shift represents less. The direction must follow the mechanism, not a memorised list.

A drought can shift agricultural supply left; a productivity-improving irrigation system can shift it right, though the final effect may depend on costs and scale.

A rise in the product’s own price is not by itself a supply shift; it is a movement along supply.