The lecture begins by highlighting the importance of the entrepreneur for the economic process and by coitizing mainstream managerial economics for not paying enough attention to this. Austrian economics, by contrast, provides a theory of the entrepreneur, who is acting in an uncertain context about changes in consumer preferences, technology, and factor prices. The most important signal for determining whether entrepreneurs are successful in anticipating consumers' demand are their profits, which are defined as the residual that remains once factor costs are subtracted from revenues. Additionally, examples for entrepreneurship as well as the inefficiency of government investment are discussed.