Using diagrams for both the industry and a representative firm, illustrate competitive long-run equilibrium.

Assuming constant costs employ these diagrams to show how (a) an increase (b) a decrease in market demand will upset that long-run equilibrium.

Trace graphically and describe verbally the adjustment processes by which long-run equilibrium is restored. Now rework your analysis for increasing- and decreasing-cost industries and compare the three long-run supply curves.