Structuration informationnelle centralisée et hiérarchisée. Une contribution à la théorie des organisations

[fre] The theory of organisations is presently the under-developped part of Economies. It should at least be able to explain why centralized structures and hierarchies are so common in societies. The existence of these structures has two reasons. One is the logics of domination and the necessities of coordination constraints. The other one stems from the means and needs of information transfers in society. This article studies the latter effect. It proves the following theorem : the optimal structure of a network of information channels between members of a society is centralized if each member must receive from each other one an information which is specific according to the receiver, and if channels are sufficiently more expensive than messages. This result is the starting point of a more developped theory, the main directions of which are mentioned here. Then, this article shows why hierarchy can be the optimal structure for informational reasons, and how some decentralization of decisions is possible in such an organization by considering hierarchy as a sequential division of labor. [eng] The theory of organisations is presently the under-developped part of Economies. It should at least be able to explain why centralized structures and hierarchies are so common in societies. The existence of these structures has two reasons. One is the logics of domination and the necessities of coordination constraints. The other one stems from the means and needs of information transfers in society. This article studies the latter effect. It proves the following theorem : the optimal structure of a network of information channels between members of a society is centralized if each member must receive from each other one an information which is specific according to the receiver, and if channels are sufficiently more expensive than messages. This result is the starting point of a more developped theory, the main directions of which are mentioned here. Then, this article shows why hierarchy can be the optimal structure for informational reasons, and how some decentralization of decisions is possible in such an organization by considering hierarchy as a sequential division of labor.