Complex Contagion: Unfolding and Control

Network cascades are a pervasive phenomenon, with examples ranging from supply chain disruptions, traffic congestions, power outages, and default contagion in financial networks to the spread of misinformation. Such cascades propagate through underlying networks, but in contrast with their epidemic counterparts, they constitute a form of "complex contagion," in the sense that the "infection" of a new component may require exposure to multiple infected components. Compared to other network spreading processes, cascades may be harder to trigger but also harder to mitigate. In this talk, I will discuss unique ways in which cascades evade mitigation and then present effective mitigation strategies that avoid evasion. The conclusions are relevant in face of the plethora of ripple effects caused by the ongoing pandemic on a multitude of local and global networks.