The article discusses two concepts of economic analysis in the United States--monopolistic competition and workable competition. Monopolistic competition theory is defined by eleven essential elements such as the idea that decisions are made to produce maximum profit in the market, short-run and long-run. Monopolistic competition is a system of theorems where the conclusion of one is the premise in another. The progressive concept of workable competition, introduced by J. M. Clark in 1940, refers to pure or perfect competition as a standard. Topics include price cutting in oligopoly, "as if collusion," price discrimination, the effect of consumer purchasing power on business cycles, market share, idle capacity, and expansionist activity in workable competition.