The cooperative enterprises in the Province of Modena are ‘long life’ economic species. Their longevity increases as their ability in developing a network interactions increases. The definition of economic efficiency of the cooperative enterprise is discussed from an institutional perspective attempting to identify a connecting path, from the traditional to the evolutionary-historical point of view. The key-concept examined is that of transaction costs, as the costs of altering the division of labour. Then, the cooperative enterprise appears as both an individual firm and as aggregate movement of firms, that is network of firm relationships, which focus on economising on such costs. In fact, the cooperative movement has deeply reduced the number and the cost of many transactions in the economic system. Overall cooperatives - like enterprises - profited from reduction of such costs, which are often present in other areas and economic contexts. The present paper finds that all of these factors tend to indicate an evolutionarily, efficient path of development, and are the principal reasons for the greater longevity of this enterprise form.