Constrained by Cost

Consider the hot fudge sundae selling activities of the Hot Momma Fudge Bananarama Ice Cream Shoppe. Hot Momma Fudge is willing and able to produce 50 Hot Momma Fudge Bananarama Ice Cream Sundaes at a $3 supply price. This price allows Hot Momma Fudge to cover the cost of ice cream, hot fudge, bananas, workers, plastic dishes, electricity, and the other production inputs. However, should Hot Momma Fudge try to produce 51, the opportunity cost exceeds this $3 price.

On the Supply Curve

Consider the supply curve for electronic calculators displayed in the exhibit to the right. For a supply price of $15, the quantity supplied is 200 calculators. Would calculator sellers be willing to sell fewer than 200 calculators at this price? Certainly. In so doing, their production cost is lower and profit is higher. Would calculator sellers be willing to sell more than 200 calculators at this price? Certainly not.

The story is the same for any quantity. Only the numbers differ. For a supply price of $45, the quantity supplied is 800 calculators. Sellers are willing to sell fewer than 800 calculators at this price, but not more.

Quantity Supplied, Not Supply

• Quantity supplied is the specific quantity that sellers supply at a specific supply price. Quantity supplied is matched up with a specific price. Should the price change, then so too does the quantity supplied. Quantity supplied is a single number.


• Supply, however, is the range of prices and quantities. It is all price-quantity pairs that make up the supply curve. Supply is a whole range of numbers.