Figure 3-6 An Increase in the Supply of Apples
apples supplied to the price of apples; its positive slope indicates that
quantity supplied increases as price increases.
The supply curve represents the relationship between quantity supplied and price, other
things being equal; its positive slope indicates that quantity supplied increases when price
increases.When economists make statements about the conditions of supply, they
are not referring just to the particular quantity being supplied at the
moment—that is, not to just one point on the supply curve. Instead, they
are referring to the entire supply curve, to the complete relationship
between desired sales and all possible prices of the product. Supply
refers to the entire relationship between the quantity supplied of a
product and the price of that product, other things being equal. A single
point on the supply curve refers to the quantity supplied at that price.
Shifts in the Supply Curve
A shift in the supply curve means that at each price there is a change in
the quantity supplied. An increase in the quantity supplied at each price is
shown in Figure 3-6. This change appears as a rightward shift in the
supply curve. In contrast, a decrease in the quantity supplied at each price
would appear as a leftward shift. For supply, as for demand, there is an
important general rule: