In economics, a deadweight loss (also known as excess burden or allocative inefficiency) is a loss of economic efficiency that can occur when equilibrium for a good or service is not achieved or is not achievable.n a perfectly competitive market, producers would have to charge a price of 10 cents and every customer whose marginal benefit exceeds 10 cents would have a nail. However, if there is one producer who has a monopoly on the product, then they will charge whatever price will yield the greatest profit.