A Duopoly Example: Price and Quantity Supplied The socially efficient quantity of water is 120 gallons, but a monopolist would produce only 60 gallons of water. e So what outcome then could be expected from duopolists? H arc Inc items and derived items copyright o 2001 by Harcourt, IncHarcourt, Inc. items and derived items copyright © 2001 by Harcourt, Inc. A Duopoly Example: Price and Quantity Supplied uThe socially efficient quantity of water is 120 gallons, but a monopolist would produce only 60 gallons of water. uSo what outcome then could be expected from duopolists?