The market for Aluminum and Welfare economics If the aluminum factories emit pollution(a negative externality), then the cost to society of producing aluminum is larger than the cost to aluminum producers. H arc Inc items and derived items copyright o 2001 by Harcourt, IncHarcourt, Inc. items and derived items copyright © 2001 by Harcourt, Inc. The Market for Aluminum and Welfare Economics If the aluminum factories emit pollution (a negative externality), then the cost to society of producing aluminum is larger than the cost to aluminum producers