Coupling spreads failure
One of five posted claims tested on 30 October 2026.
The posted claim
Coupling networks together improves efficiency and creates failure paths that
neither network had; cascades should be larger in coupled systems.
What we did
Two Erdős–Rényi networks (N = 20,000, mean degree 4) coupled node-to-node. A fraction φ is removed from both, and a mutual-giant-component cascade propagates through the dependency links (Buldyrev et al. 2010).
What we found
The coupled system collapses (survival < 5%) at φ = 0.60, where a single network still has 24.9% of its nodes and collapses only at φ = 0.75. At φ = 0.60 the coupled system retains 0.7% of nodes — a 24-percentage-point coupling penalty.
Verdict: Supported.