Soutenance de thèse Qiang CAO - 22 décembre 2025

PhD Defense – Qiang Cao– 22 December 2025

Qiang Cao, PhD candidate at UMR SADAPT – Université Paris-Saclay, is pleased to invite you to his PhD defense entitled “The role of multiplex networks in innovation processes: The case of China’s seed industry”.

The defense will be held online on Monday, 22 December 2025.
The precise time of the defense and the videoconference link will be provided at a later date.

This PhD was conducted within the UMR SADAPT (Université Paris-Saclay, INRAE, AgroParisTech), under the supervision of André TORRE, Research Director, and the co-supervision of Maryline FILIPPI, Professor.

The jury will be composed of:

• Vanessa CASADELLA – Professor, Université de Picardie Jules Verne – Reviewer & Examiner
• Rosella NICOLINI – Professor, Universitat Autònoma de Barcelona (Spain) – Reviewer & Examiner
• Jean-Philippe DENIS – Professor, Université Paris-Saclay – Examiner
• Sébastien BOURDIN – Professor, EM Normandie Business School – Examiner
• Henri L.F. DE GROOT – Professor, Vrije Universiteit Amsterdam – Examiner
• Tom BROEKEL – Professor, University of Stavanger (Norway) – Examiner

Abstract: Behind innovation outcomes lie complex networks embedded within various territories. While economic geographers have examined the multiscalar dimensions of these networks, the nonlinear and spatial nature of innovation—which involves diverse actors connected through multiple types of relations—remains undertheorized. Furthermore, these dynamics are under-examined within the critical agricultural sector. This PhD thesis addresses these gaps by developing and applying a multiplex network framework to analyze how network scales and structures shape innovation processes and outcomes. The case of China's seed industry, a strategic component of the global food supply chain, is under examination.

The thesis provides a comprehensive review of innovation studies in agriculture and agri-business. It contributes to enhancing our understanding of "what" innovation activities have received attention, "how" scholars from various disciplinary backgrounds have approached this topic, and "why" it is crucial to better comprehend innovation processes in agriculture. Then, it presents three empirical studies: one examines the national tomato seed sector, while the other two focus on the local vegetable seed industry. Collectively, these studies offer a threefold contribution. Theoretically, they demonstrate the necessity of integrating a nonlinear, multiplex perspective into economic geography's understanding of innovation processes and outcomes. Methodologically, they advance the application of multiplex network analysis to nonlinear innovation. Empirically, they provide rare, in-depth examination of relational dynamics driving innovation and linking the global seed industry to local clusters. At the policy level, the thesis offers actionable insights for promoting innovation and development within the national seed industry and in agricluster contexts.

Keywords: Innovation, Multiplex Networks, Knowledge, Periphery, Seed Industry, China