The hypothesis of rational decision theory is: the hypothesis of decision maker. Simon constructed the decision-maker hypothesis in a series of papers and decision-making theory works. The main viewpoints include: rationality is limited; Seek a satisfactory solution; Organization is a balanced system of "induction and contribution". The core of the decision maker's hypothesis is to assume that all operators are regarded as the main body to take corresponding actions after making independent decisions. Decision-making is a process of drawing conclusions from premises, and there are two premises: fact premise and value premise. The fact premise comes from experience, knowledge and intelligence, which must be rational and logical; The premise of value comes from emotion, motivation and need, and is full of value.

Decision maker hypothesis is a decision maker hypothesis constructed by Simon in a series of papers and works on decision theory.

The assumption of "decision maker" is to analyze people's behavior under a specific organizational background and fully consider people's physiological and psychological characteristics (mainly information processing ability). It does not make an eternal transcendental setting for the purpose and corresponding means of human activities, but regards the purpose and means as variables that can be adjusted within a certain range. Its focus is not on tracing the causal chain of individual efficiency, but on behavioral coordination in group rational decision-making. Compared with "economic man" and "social man", the fullness and reality of this hypothesis of human nature are obvious. The decision-making school of management theory developed from this has naturally attracted widespread attention. At the same time, this assumption is implicitly or explicitly included in the institutional premises-contingency school, management process school and management science school, and has become a more recognized human nature assumption in management theory.

The emergence of the "decision-maker" hypothesis marks an important change in management theory: from focusing on improving efficiency to rational decision-making. Simon's famous proposition "management is decision-making" is a concise summary of this turn. This turn has important practical and theoretical significance.