Sandpile Economics is a book about why modern economies often appear stable until they suddenly are not. It argues that crises rarely emerge from isolated shocks alone; they emerge from systems that have accumulated hidden fragility through efficiency, concentration, specialization, leverage, and interdependence. Using examples from financial crises, supply-chain disruptions, energy dependence, sovereign debt, AI infrastructure, climate finance, and global production networks, the book shows how small disturbances can become large avalanches when they hit the wrong structural point. Its purpose is not to predict the exact next crisis, but to offer a new way of seeing fragility before it becomes visible: as a geometry of slopes, bottlenecks, thresholds, and propagation paths that shape the behavior of firms, markets, governments, and global institutions.
Chapter 0 — Rationale and Opening Argument (here)
Part I — Why Modern Economies Break
Chapter 1 — Lehman, Suez, Hormuz, and a German Chemical Plant Without Gas
The book opens with four seemingly unrelated episodes to show how local shocks can become systemic crises. (here)
Chapter 2 — The Sandpile Idea
This chapter introduces the core idea of the book: economic systems slowly accumulate fragility until a small disturbance can trigger an avalanche. (here) Econometric Working paper (here).
Chapter 3 — Why Networks Are Different
Here I explain why national averages and aggregate indicators often hide the real structure of risk. (here)
Part II — The Hidden Geometry of Fragility
Chapter 4 — The Map Beneath the Map
This chapter presents the idea that every economic network has a hidden geometry that shapes how shocks travel and amplify. (here)
Chapter 5 — When Efficiency Becomes Fragility
This chapter examines how the search for efficiency, when it removes too much redundancy, can turn optimized systems into fragile ones. (here)
Chapter 6 — Reading Avalanches Before They Happen
Here I develop the central prevention question: if fragility has structure, then it can also be measured before the crisis. (here)
Part III — Sandpile Economics in History
Chapter 7 — 2008: The Geometry of a Financial Avalanche
This chapter interprets the global financial crisis as a network avalanche, where fragility accumulated before traditional indicators reacted. (here)
Chapter 8 — The Day the World’s Supply Chains Sneezed
This chapter analyzes the pandemic and the Suez blockage as signals of the same logistical fragility accumulated over decades. (here)
Chapter 9 — The German Energy Trap
This chapter studies how Germany’s energy dependence shifted from competitive advantage to structural vulnerability. (here)
Chapter 10 — Sovereign Sandpiles: Latin America and the Architecture of Debt Crises
Here I apply the framework to sovereign debt crises, showing how capital flows can synchronize vulnerabilities across countries. (here)
Part IV — Living in a Sandpile World
Chapter 11 — What Boards and CEOs Should Do Differently
This chapter translates the conceptual framework into practical questions for boards, CEOs, and risk teams. (here)
Chapter 12 — What Central Banks and Regulators Should Do Differently
This chapter argues for complementing traditional supervision with a network-based reading of systemic fragility before crises occur. (here)
Chapter 13 — The Decade Ahead
The book closes by looking at the sandpiles now forming: climate-transition finance, AI infrastructure, critical minerals, geopolitical fragmentation, and sovereign debt. (here)
Full book available for download: The complete draft of Sandpile Economics can be downloaded [here].
The purpose is not to publish a book as a closed product, but to open a conversation. Each chapter shares evidence, intuitions, and tools for thinking about why modern economies break — and how we might learn to see it coming.
Please cite: Vallarino, D. (2026). Sandpile Economics: the Geometry of Fragility in Modern Economic Systems [Open online book]. https://www.diegovallarino.com/new-book