Demand

Statement

Demand refers to the quantity of a good or service that consumers are willing and able to buy at various prices over a given period of time, ceteris paribus.

Notes

Demand is effective demand — it counts only wants backed by both willingness and ability to pay, not mere desire. In the H2 syllabus the demand curve refers to market demand, the collective demand of all consumers in the market for a single good. Quantity demanded — a single point on the curve, the amount bought at one price — must be kept distinct from demand, the whole curve: a change in the good’s own price moves quantity demanded along the curve, whereas a change in a non-price determinant shifts demand. The inverse price–quantity relationship is the law of demand.