What does "change in quantity supplied" refer to?

The phrase "change in quantity supplied" specifically refers to a movement from one point to another on a fixed supply curve. This indicates that suppliers are willing and able to produce different quantities of a good or service at different price levels, while the overall supply curve remains unchanged.

In this context, a change in quantity supplied is prompted solely by a change in the price of the good itself. For example, if the price rises, producers may increase their output, resulting in a higher quantity supplied. Conversely, if the price falls, the quantity supplied decreases. This concept revolves around the existing supply conditions, emphasizing the relationship between price and the quantity suppliers are willing to offer, rather than altering the supply curve itself, which would be indicative of a change in supply.

By contrast, if there is a shift of the entire supply curve, it indicates a change in supply due to factors other than price, such as changes in production costs or technology, which is not what "change in quantity supplied" indicates. Therefore, focusing solely on movements along the existing supply curve, rather than the curve itself, clarifies the concept.