The market supply curve is found by
A) horizontally summing all individual supply curves.
B) vertically summing all individual supply curves.
C) Either A or B above since they both give the same answer.
D) None of the above.

Question

Quizplus · Accepted Answer

The market supply curve represents the total quantity supplied by all firms in the market at different prices. To find the market supply curve, we must add up the quantities supplied by each individual firm at each price level. Since the supply curves of individual firms are graphed on a price-quantity plane, we add their quantities horizontally (along the x-axis) to get the market supply curve. Therefore, the correct answer is A.

The Market Supply Curve Is Found by