Movement Along the Supply Curve
A movement along the supply curve represents the response of the quantity supplied to changes in the price in the supply curve graph. An increase in price generates an upward movement along the supply curve, while a decrease in price generates a downward movement.
Graph of Movements Along the Supply Curve
As shown in the graph, an increase in price from 60 to 80 generates an increase in the quantity supplied from 400 to 600, moving from point C to point D. Conversely, a decrease in price from 60 to 40 generates a downward movement along the supply curve, reducing the quantity supplied from 400 to 200.
It is important to differentiate between a movement along the supply curve and a shift of the supply curve. When one of the variables on the axes changes, that is, price or quantities, a movement along the curve is generated. When any other variable besides price or quantities that can affect the quantity supplied changes, such as production costs, wages, or regulations, a shift of the supply curve is generated. A movement along the supply curve is called a "change in quantity supplied," while a shift of the supply curve is called a "change in supply."