Entrepreneurship is one of the least understood topics in economics. The rising significance of small companies and especially of start-ups for the creation of new jobs has been an intensively discussed subject for nearly one decade. But there is still no theory of entrepreneurship.
First this paper reviews the role of the entrepreneur in the history of economic thought and concludes that there is no agreed upon definition of what an entrepreneur does or is. The unsolved problem is the non-rational human behavior. Schumpeter and Kirzner have developed economic models of the role of the non-maximizing entrepreneur in the price-mechanism. But they did not develop a theory of entrepreneurship.
In the second part of the paper entrepreneurship is understood as the pursuit of opportunites without regard to resources currently controlled (Stevenson, Roberts, and Grousbeck). Based on that definition the contributions of economic decision theory, sociological system theory, psychoanalytical research and behavioral studies are reviewed and an interdisciplinary approach to the development of an entrepreneurship theory is proposed.