How a Constant Cost Industry Adjusts to an Increase in Demand The top panel shows the initial industry and firm equilibrium. The market price for domain name registration is $6.99 and each firm is making a normal profit. In the middle panel, the demand for registration increases, which pushes up the market price to $7.99. In the short run, each firm in the industry expands along its MC curve and thus market quantity increases to Qsr. Each firm earns above-normal profits. In the bottom panel, the above-normal profits attract entry. As more firms enter the industry, the short-run supply curve shifts to the right and as it does price falls. Firms continue to enter and the price continues to fall until price returns to $6.99. At that price, firms are once again earning normal (zero) profits since P = AC.