Economic efficiency is defined as a market outcome in which the marginal benefit to consumers of the last unit produced is equal to the marginal cost of production, and in which January 1, 2023 by admin the sum of consumer surplus and producer surplus is at a maximum. economic surplus is minimised. the sum of the benefits to firms is equal to the sum of the benefits to consumers. the sum of consumer surplus and producer surplus is minimised. See Answer the sum of consumer surplus and producer surplus is at a maximum.