Competition arises whenever two or more parties strive for something that all cannot obtain. The classical economists felt no need for a very precise definition of competition because they viewed monopoly as highly exceptional. In the late 19th century competition became the subject of intense analysis; the concept of perfect competition emerged as the standard model of economic theory and as first approximation in the concrete studies of applied microeconomics. The limitations of the concept in dealing with conditions of persistent and imperfectly predicted change will be removed only when economics possesses a developed theory of change.