The new post-neoclassic economic approaches developed by the Behavioural Economics and the New Institutional Economics theories opened the door for non economical disciplines to explain the real economic behavior of the agents (individuals, organizations, companies and government). Within this disciplines, economists began to integrate the media and the media theory into the economic theory. This new research approach for Media Economics and Media Management is signi cant because it focus on the social function of the communication industry from an economic perspective. Also, it represents an opportunity for media scholars to advance in the understanding of the functions of the media in a given economic system and its development, the use that the audience does of the economic information and media, and the sources of value creation for this media companies. From this new perspective, four functions and sources to create value for the economic media companies where analyzed: i) the diffusion of the information and meanings that promotes people’s par- ticipation in the economic and nancial systems; ii) the impact in the information asymmetry and transaction costs in the markets; iii) the enhancement of the coordination between the economic agents that allows the implementation of policies for economic development; iv) the creation of ideological platforms of debate that contribute to the diffusion and social validation of economic ideas that allow the coordination mentioned above. The study of the case of Expansión shows how this business media performed the rst two functions to become the leader of the segment for more than 20 years, but couldn’t ful ll the other two. Therefore, it was not able to become a public reference and authority as the general information media, just like happened with other economic newspapers in Europe or the Wall Street Journal in the United States.