This book offers a rigorous discussion on how we can understand economic systems through a complexity lens. In particular, the author investigates the relationships between the firms, the industries, and markets (micro, meso, macro relationships), in order to help us better understand the main challenges of a representation of the economy using the "complex systems' theory". The author argues that the logic of governance in the paradigm of complex systemic rationality renounces anthropocentric vision of the organization and the possibility of total direction and control over systemic and intersystemic relations and accept a constructivist vision of these relations and their mutual interdependencies. Offering a novel perspective, this book contributes to improve our understanding of economic complex systems and how organizations at different levels interact.